Lateral gas line configuration

ABSTRACT

A mask for patient ventilation comprises a frame portion, a front portion, a retention strap, and a gas delivery orifice. The frame portion is for surrounding a respiratory opening of a patient. The front portion is coupled with the frame portion and covers the respiratory opening region. The retention strap is for maintaining positive pressure between the frame portion and the patient. The gas delivery orifice is coupled with the frame portion and configured such that the gas delivery orifice is lateral to the front portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is related to U.S. patent application Ser. No.13/105,738 entitled ADJUSTING A VENTILATION MASK, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,757 entitled CORRUGATED FLEXIBLE SEAL OF A VENTILATION MASK,filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,773 entitled NASAL PASSAGE OPENER OF A VENTILATION MASK, filedMay 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,782 entitled A CARBON-DIOXIDE SAMPLING DEVICE FOR NONINVASIVELYMEASURING CARBON DIOXIDE IN EXHALED BREATH, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,840 entitled A CARBON-DIOXIDE SAMPLING SYSTEM FOR ACCURATELYMONITORING CARBON DIOXIDE IN EXHALED BREATH, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,793 entitled INTERCHANGEABLE INSERTS, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,821 entitled QUICK DONNING HEADGEAR, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,829 entitled SMART CONNECTIONS, filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,848 entitled TUBE PLACEMENT IN NON-INVASIVE VENTILATION, filedMay 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,851 entitled NON-INVASIVE VENTILATION EXHAUST GAS VENTING, filedMay 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,861 entitled NON-INVASIVE VENTILATION FACIAL SKIN PROTECTION,filed May 11, 2011.

This Application is related to U.S. patent application Ser. No.13/105,871 entitled NON-INVASIVE VENTILATION FACIAL SKIN PROTECTION,filed May 11, 2011.

BACKGROUND

Non-invasive ventilation involves the delivery of fresh respiratorygases to a patient through a non-invasive means such as a mask, hood, orhelmet rather than through an invasive means such as an endotrachealtube inserted via an oral, nasal, or tracheal opening in a patient.Continuous positive airway pressure (CPAP) ventilation and bi-levelventilation are two specific techniques of non-invasive ventilation.CPAP ventilation, as implied by the name, provides a continuous pressureof air during ventilation which maintains the airway in an open stateand thus can fill the lungs with air thus requiring less work fromrespiratory muscles. CPAP is often used for patients with respiratoryfailure or near respiratory failure and for individuals with sleepapnea. Bi-level or variable level ventilation is often used for sleepapnea patients and for non-invasive ventilation for respiratoryinsufficiency or failure in institutional and home setting and issimilar to CPAP, except that pressure is varied during inspiration andexpiration. For example, pressure is lowered during expiration to easeexhalation. Compared with invasive ventilation, non-invasive ventilationcan result in lower patient stress levels and lower trauma to patientairways. As such, non-invasive ventilation techniques offer more patientcomfort than invasive ventilation techniques.

There are three major components involved in non-invasive ventilation: aventilator which is an item of hardware which supplies fresh respiratorygas(es); a patient interface such as a mask; and a breathing circuit(i.e., tubes and connectors) that couple the ventilator with mask suchthat the fresh respiratory gases can be supplied to the patient forbreathing. There are generally two techniques of non-invasiveventilation that are commonly in use: single limb, and dual limb.

Single limb breathing circuit applications involve blowing high flowlevels of fresh respiratory gas into the patient interface, and relyingon vent ports in the patient interface for allowing exhaled respiratorygases to exit the patient interface into the atmosphere. Vent ports orvents are designated leakage points that allow for a controlled leakage,or venting, of fresh respiratory gases in order to maintain a desiredpressure of respiratory gases within a patient interface and to clearexhaled carbon dioxide. “Single limb” refers to the fact that aventilation limb or limbs coupled with a patient interface only supplyfresh respiratory gas and do not provide a return path for exhaledgases. As such, in some “single limb” applications a fresh respiratorygas supply tube may split into two or more tubes/limbs that allow freshrespiratory gas to enter a patient interface via more than one location.Because of the presence and reliance on vents, single limb non-invasiveventilation is also referred to as vented non-invasive ventilation.

Dual limb breathing circuit applications involve respiratory gases beingblown into a patient interface via a first limb and exhaust gases beingevacuated from the patient interface via a second, separate limb.Because of the second limb which is used for evacuation of exhaustgases, no vents are needed in the patient interface for venting exhaustgases into the atmosphere. Because no vents are required, dual limbnon-invasive ventilation is also referred to as non-vented non-invasiveventilation.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis application, illustrate embodiments of the subject matter, andtogether with the Description of Embodiments, serve to explain theprinciples of the embodiments of the subject matter. Unless noted, thedrawings referred to in this brief description of drawings should beunderstood as not being drawn to scale.

FIG. 1 shows a front perspective view of an example non-invasiveventilation system, in accordance with various embodiments.

FIG. 2 is rear perspective of a patient interface of a non-invasiveventilation system, in accordance with various embodiments.

FIG. 3 shows a front perspective view of patient interface of anon-invasive ventilation system and illustrates a removal/insertion ofan interchangeable patient interface insert, in accordance with anembodiment.

FIG. 4 shows a front perspective view of patient interface of anon-invasive ventilation system and illustrates an interchangeablepatient interface insert which includes a self-sealing access port, inaccordance with an embodiment.

FIG. 5 shows a front perspective view of patient interface of anon-invasive ventilation system and illustrates an interchangeablepatient interface insert which includes a breath sampling port, inaccordance with an embodiment.

FIG. 6 shows a front perspective view of patient interface of anon-invasive ventilation system and illustrates a self-sealing gastrictube insertion region disposed within the facial skin interface, inaccordance with an embodiment.

FIG. 7 shows a front perspective view of a doffed patient interface of anon-invasive ventilation system, in accordance with an embodiment, andalso illustrates an interchangeable patient interface insert whichincludes built-in filter media, in accordance with an embodiment.

FIGS. 8A and 8B shows front perspective views of patient interfaces of anon-invasive ventilation system which are configured with a zygomaticfacial interface and illustrate interchangeable patient interfaceinserts which include an aviator style fresh respiratory gas interface,in accordance with various embodiments.

FIG. 9 shows a method for adjusting a ventilation mask, in accordance toan embodiment.

FIG. 10 shows a method for adjusting a ventilation mask, in accordanceto an embodiment.

FIG. 11 shows a method for assisting in opening a nasal passage, inaccordance to an embodiment.

FIG. 12 shows a front perspective view of a non-invasive patientinterface with carbon-dioxide sampling device for non-invasivelymeasuring carbon dioxide in exhaled breath, in accordance with anembodiment.

FIG. 13 shows a cross-sectional view of the non-invasive patientinterface of FIG. 12 illustrating the carbon-dioxide sampling deviceincluding a carbon dioxide collector, in accordance with an embodiment.

FIG. 14 shows a schematic diagram of a carbon-dioxide analyzer forconverting a sample of exhaled breath from the patient into ameasurement of carbon dioxide content in the sample of exhaled breathfrom the patient, in accordance with an embodiment.

FIG. 15 shows a schematic diagram of an alternative embodiment for thecarbon-dioxide analyzer for converting a sensor signal form acarbon-dioxide sensor into a measurement of carbon dioxide content in asample of exhaled breath from the patient, in accordance with anembodiment.

FIG. 16 shows a flowchart of a method for non-invasively measuringcarbon dioxide in exhaled breath, in accordance with an embodiment.

FIG. 17 shows a schematic diagram of a carbon-dioxide sampling systemfor accurately monitoring carbon dioxide in exhaled breath, inaccordance with an embodiment.

FIG. 18 shows a front perspective view of the non-invasive patientinterface of a combined non-invasive patient interface andcarbon-dioxide sampling system, in accordance with an embodiment.

FIG. 19 shows a schematic diagram of a carbon-dioxide analyzer includinga carbon-dioxide sensor configured to sense a level of carbon dioxide inexhaled breath of the patient, in accordance with an embodiment.

FIG. 20 shows a schematic diagram of a combination carbon-dioxidemeasurement display and recorder, in accordance with an embodiment.

FIG. 21 shows a flowchart of a method for accurately monitoring carbondioxide in exhaled breath, in accordance with an embodiment.

FIG. 22 is a flow diagram of an exemplary method for accessing arespiratory opening of a patient without removing a ventilation mask inaccordance with an embodiment.

FIG. 23 is shows a front perspective view of a doffed patient interfaceof a non-invasive ventilation system with a smart component, inaccordance with an embodiment, and also illustrates a ventilator withcapability of determining system configuration, in accordance with anembodiment.

FIG. 24 is a flow diagram of an exemplary method for determiningcontinuity of a ventilation system in accordance with an embodiment.

FIG. 25 is a flow diagram of an exemplary method for determiningconfiguration of a ventilation system in accordance with an embodiment.

FIGS. 26A-26C illustrate detail views of a self-sealing tube insertionregion, according to various embodiments.

FIG. 27 illustrates a replaceable filter cartridge, in accordance withan embodiment.

FIG. 28 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal and a facial skin interface, according toan embodiment.

FIG. 29 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal and a facial skin interface, according toan embodiment.

FIG. 30 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal and a facial skin interface, according toan embodiment.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. While the subjectmatter will be described in conjunction with these embodiments, it willbe understood that they are not intended to limit the subject matter tothese embodiments. On the contrary, the subject matter described hereinis intended to cover alternatives, modifications and equivalents, whichmay be included within the spirit and scope. Furthermore, in thefollowing description, numerous specific details are set forth in orderto provide a thorough understanding of the subject matter. However, someembodiments may be practiced without these specific details. In otherinstances, well-known structures and components have not been describedin detail as not to unnecessarily obscure aspects of the subject matter.

Overview of Discussion

Herein, various embodiments of a non-invasive ventilation patientinterface, system, and components thereof are described. Variousembodiments described herein can be utilized across the spectrum ofnon-invasive ventilation, from spontaneously breathing patients who needsome respiratory assistance to patient who are unable to breathe withoutmechanical assistance. For purposes of the present description, itshould be appreciated that many of the described patient interfaceembodiments may be utilized with both single limb and dual limbventilation applications, and may in many cases be switched over fromone to another by reconfiguring a ventilator and in some instancesreconfiguring or replacing one or more components. Description beginswith a general discussion of major components and features associatedwith the non-invasive ventilation technology described herein. Thisgeneral discussion provides a framework of understanding for moreparticularized description which follows in thirteen separate sections.These thirteen sections are dedicated and focused on detailed discussionof particular features and concepts of operation associated with one ormore embodiments of the described non-invasive ventilation technology.

Major Components and Features

FIG. 1 shows a front perspective view of an example non-invasiveventilation system 100, in accordance with various embodiments.Non-invasive ventilation system 100 comprises three major components,patient interface 110 (also referred to herein as mask 110), breathingcircuit 140, and ventilator 160. Ventilator 160 supplies freshbreathable respiratory gas such as oxygen or other repertory gas(es).Breathing circuit 140 fluidly couples the fresh respiratory gas fromventilator 160 to patient interface 110. Patient interface 110 sealablycouples in a controlled seal (controlled in the sense that intentionalleaks are permitted while unintentional leaks are reduced or eliminated)over at least one respiratory opening of patient 101 to form a hollowchamber into which fresh respiratory gas is coupled via breathingcircuit 140. Although patient interface 110 is illustrated in FIG. 1 andthroughout as covering both the nasal and oral cavities (nose andmouth), some embodiments may cover only a nasal cavity or oral cavity,or may capture the entire face or head of a patient. Thus, in general,embodiments of patient interface 110 can be said to couple in acontrolled seal over a respiratory opening of a patient, where arespiratory opening may include a nasal cavity, an oral opening, boththe nasal and oral cavities of a patient, the entire face of a patient(encompassing the nasal and oral cavities), or the entire head of apatient (encompassing the nasal and oral cavities).

As illustrated, respiratory gas tube 141 and y-piece 142 provide atubular path for fluidly coupling limbs 143 and 144 of patient interface110 with ventilator 160. In some embodiments, y-piece 142 may includeone or more swiveling portions to relieve torque and allow forarticulation of breathing circuit 140. In some embodiments, limbs 143and 144 may both be inhalation gas supply lines for supplying freshrespiratory gas for breathing by patient 101. In other embodiments, oneof limbs 143 or 144 acts as an inhalation gas supply line, while theother of limbs 143 and 144 acts as an exhalation gas collection line forcollecting exhaust gas (exhaled breath and unused respiratory gases)from patient 101. Although limb 143 is illustrated herein as a singletube, it is appreciated that, in some embodiments, limb 143 may be aplurality of smaller tubes. Such a configuration of limb 143 facilitatesthe plurality of smaller tube lying more or less flatly against andflexibly following the contour of the face of patient 101 or of a sidestrap of head strap system 111. Similarly, although limb 144 isillustrated herein as a single tube, it is appreciated that, in someembodiments, limb 144 may be a plurality of smaller tubes. Such aconfiguration of limb 144 facilitates a the plurality of smaller tubeslying more or less flatly against and flexibly following the contour ofthe face of patient 101 or of a side strap of head strap system 111.

In one embodiment, respiratory gas tube 141 fluidly couples withventilator 160 via a respiratory gas port 161. All though not depictedin FIG. 1, in some embodiments, ventilator 160 may include a pluralityof respiratory gas ports and/or other ports such as exhaled gas returnport(s) and/or a carbon dioxide monitoring port. In some embodiments,respiratory gas port 161 and/or other connections and tubes in breathingcircuit 140 may, among other things, self-identify to ventilator 160whether patient interface 110 is a vented or non-vented patientinterface and/or whether patient interface 110 is a neonatal, child, oradult patient interface. Furthermore, in some embodiments, connectorsand ports of breathing circuit 140 are designed such at they only couplewith compatible components. Thus, in one embodiment, neonatal connectorswould only couple with a neonatal patient interface and a neonatalrespiratory gas port 161. In one embodiment, child connectors would onlycouple with a child patient interface and a child respiratory gas port161. In one embodiment, adult connectors would only couple with an adultpatient interface and an adult respiratory gas port 161. These and otherfeatures of a “smart connection” protocol will be described furtherherein in a separate section below.

Anti-asphyxia valve(s) 145 (145-1, 145-2) are provided, in someembodiments, as a safety mechanism in case the flow of fresh respiratorygas fails or is interrupted. Anti-asphyxia valves 145 fail in an openposition to the external atmosphere, so that the anti-asphyxia valvewill open to the atmosphere to keep the patient from suffocating.

Patient interface 110 comprises a frame 125, a facial skin interface130, a compliant nose bridge seal 135, a domed front portion 120 (whichmay be fixed or may be a removable/interchangeable insert), and a headstrap system 111.

Head strap system 111 includes a plurality of side straps 112 (112-1,112-2, and 112-3, 112-4 (not visible in FIG. 1, but illustrated in FIG.7)) which couple with frame 125. Upper left side strap 112-1 and lowerleft side strap 112-2 couple head strap system 111 from a left lateralportion of frame 125 around the posterior skull of patient 101 and toupper right side strap 112-3 and lower right side strap 112-4. Upperright side strap 112-3 and lower right side strap 112-4 couple with aright lateral portion of frame 125. Side straps 112 are adjustable suchthat they may apply an adjustable securing force to secure nose bridgeseal 135 and facial skin interface 130 of patient interface in positionover one or more respiratory openings of patient 101. Adjustment of sidestraps 112 facilitates adjusting the fitment and seal of facial skininterface 130 to accommodate variety of patient facial sizes and shapes.

Side straps 112 couple with retention portions of frame 125, while limbs143 and 144 swivelably couple with gas ports (also referred to asorifices) disposed as portions of frame 125. These retention portionsand gas port connection features/orifices are be better illustrated andfarther discussed in conjunction with FIG. 7.

Facial skin interface 130 is coupled with nose bridge seal 135 and isdisposed between frame 125 and the chin and cheek regions of patient101. The general structure of facial skin interface 130 is such thatthere is a flexible material in contact with the face of patient 101,this allows for some movement of the patient while maintaining a sealwith the face of patient 101 so that respiratory gases do notuncontrollably leak out from between facial skin interface 130 and thefacial skin of patient 101. The flexible material may be silicone,Thermo Plastic Elastomer (TPE), two-layer or multi-layer plastic, amaterial of variable wall thickness, a combination of elastic andplastic materials, or other flexible material(s) that are known in theart. Herein flexible means that the material is capable of flexing toconform to a surface, such as a facial feature of a patient, in someembodiments, the flexible material is thinner at locations where it willcontact the face of a patient and it gets more and more thick thefurther it gets from the patient contact area. This increasing thicknessprovides some increased rigidity and provides structure. Herein, “rigid”means that a material does not tend to flex to conform to a surface,such as a facial feature of a patient. While rigidity is desired in someportions of a patient interface, lack of flexibility in regions of apatient interface which come into contact with facial skin contributesto increased unintentional leakage and also creates pressure pointswhich can skin necrosis in a relatively short period of time. Necrosisis the premature death of skin cells and can be caused by pressure pointtrauma and decreased blood circulation as a result of pressure appliedto facial skin by a patient interface. As will be further described, insome embodiments facial skin interface 130 may incorporate one or moreadditional features to allow for increased flexibility (e.g., to allowsome movement and articulation of facial skin interface 130) in order toalleviate pressure points and improve patient comfort while stillmaintaining fit such that patient ventilation is not disrupted byuncontrolled leakage of respiratory gases. Segmented sections,corrugations, ridges, bladders, and bellows are some examples of theseadditional features.

In general, the human nasal bridge has only a very thin layer of skincovering the nasal bone structures and flexible nasal cartilage. Becauseof this, the nasal bridge very susceptible to skin necrosis caused bypressure points. Additionally, portions of the nasal passages veryeasily pinch, crush, or slightly collapse in response to appliedpressure. Compliant nose bridge seal 135 couples with left and rightlateral portions of facial skin interface 130 and also couples betweenan upper portion of frame 125 and the nasal bridge of patient 101.Compliant nose bridge seal 135 is very flexible and, as such, complieswith the shape of the nasal bridge of patient 101 in response to donningof patient interface 110. Although side straps 112 of head strap system111 provide a securing force, the positioning of side straps 112 onframe 125 allow this securing force to be distributed via frame 125 tofacial skin interface 130. In this manner, facial skin interface 130mostly or entirely transfers the securing force to the chin and cheekbone/zygomatic arch regions of the face of patient 101, while little ofnone of the securing force is transferred to the nasal bridge of patient101. Instead of relying on securing force of head strap system 111 toform a seal, compliant nose bridge seal 135 employs one or more othermechanisms such as corrugated sections, inflatable/inflated bladders,medical grade foam, and/or adhesive. In some embodiments, as will bedescribed herein, when an adhesive, such as a hydro gel or pressuresensitive adhesive is utilized, nose bridge seal 135 may actually beconfigured to expand outward from the sides of the nose of patient 101so as to impart a negative or outward force on the nasal bridge regionof patient 101, while still performing a sealing function. Such anoutward force will slightly open the nasal passageways of patient 101,rather than pinching them closed.

Domed front portion 120 is, in one embodiment, made of a transparentmaterial which allows a medical care professional visibility of the oraland nasal cavities of patient 101. Domed front portion 120 is sealablycoupled with frame 125 and, in conjunction with nose bridge seal 135,facial skin interface 130, and frame 125, forms a breathing chamber fromwhich patient 101 may inhale fresh respiratory gas and into whichpatient 101 may exhale. In vented non-invasive ventilation, domed frontportion 120 may include one or more exhaust gas vent ports 123 thatallow expulsion of exhaust gas from patient interface 110 in response toexhalation of patient 101. In some embodiments, the size and arrangementof vent ports 123 is selected to allow fresh respiratory gases to escapeat a predetermined flow rate in order to assist in controlling thepressure the fresh respiratory gases near a respiratory opening (nose,mouth, or nose and mouth) of patient 101.

As previously described, in some embodiments domed front portion 120 isa removably coupled portion of patient interface 110. In removablycoupled embodiments, domed front portion 120 may be removed from patientinterface 110 while the remainder of patient interface 110 remains inplace on patient 101. Such removal of a removable coupled domed frontportion 120 can be accomplished for a variety of reasons, including: tofacilitate oral care of patient 101, to facilitate administration oforal or aerosolized medication to patient 101, to improve comfort ofpatient 101, to facilitate speech of patient 101, to clear debris (e.g.,vomit, saliva, blood, etc.) from the airway or from within patientinterface 110, and facilitate insertion and/or removal of oral or nasaltubes or medical instruments. As will be described, in some embodiments,one or more different features may be incorporated into a domed frontportion 120. In some embodiments, a domed front portion 120 may beremoved and interchangeably replaced with another domed front portion(which may offer a feature not included in the replaced domed frontportion 120). A variety of different interchangeable versions ofremovable domed front portion 120 are illustrated and described herein.Removably coupled versions of domed front portion 120 may be referred toherein as “interchangeable patient interface inserts,” “interchangeablefunctional inserts,” “interchangeable inserts,” “removable inserts,”“inserts,” or the like.

As is described herein, in some embodiments, a domed front portion 120may have a function or support some medical function or procedure, andthus a domed front portion 120 may be changed out to change functions orto facilitate performing a variety of medical functions. It is furtherappreciated that, in some embodiments, domed front portions 120 may beconfigured to operated with a person of a certain size (e.g., a child,an adolescent, a grown person, an obese person, etc.). For example, ventholes disposed in a domed front portion 120 may be configured for apredetermined breathing rate/gas flow for a person of a particular size.In some embodiments, a domed front portion 120 can thus be inserted intopatient interface 110 based upon the size of a patient 101 beingventilated.

FIG. 2 is rear perspective of a patient interface 110 of a non-invasiveventilation system 100, in accordance with various embodiments. Limbs143 and 144 (not visible) have been swiveled to a forward position andhang downward toward the chest of patient 101. As illustrated in FIG. 2,head strap system 111 defines a somewhat circular opening 211 (it maybeperfectly circular or may be somewhere between circular and oval inshape). It is appreciated that circular opening 211 may be devoid ofmaterial or may be covered by a fabric or other material. Moreover,circular opening 211 may be molded and/or may be defined by a pluralityof slits made to open a region within head strap system 111. In someembodiments, head strap system 111 is constructed from semi-rigidmaterial with an o-frame feature, defined by the coupling of side straps112-1 and 112-3 to the upper left and right lateral portions of frame125. This O-frame feature captures the top of the head while circularopening 211 cradles the occipital region of the rear skull of patient101. The semi-rigid construction of head strap system 111 provides someamount of inherent rigidity so that when it is in storage, it can becollapsed or folded; but when it's removed from collapsed storage, iteasily and naturally returns to a general head shaped structure, so thatit is visibly obvious how to position and install head strap system 111on patient 101 when donning patient interface 110. In this manner, thereis no need to sort out where the front, back, top, or bottom is located.In one embodiment, patient interface 110 is packaged with head strapsystem 111 already pre-attached with frame 125, so that when unpackagedthe semi-rigid structure of head strap system 111 causes it to looksomewhat like a helmet that can just be pulled quickly over the head andface area of patient 101, much like putting on a catcher's mask.

Also depicted in FIG. 2 is a quick release rip cord type pull-tab 212.The positioning of the quick release pull tab 212 may be in differentlocations than illustrated and additional pull-tabs may be included insome embodiments. As illustrated, pull-tab 212 is located near the upperposterior skull and couples with head strap system 111. Pull-tab 212 iseasy to access and grasp by both a patient and by a medical careprofessional. Pull-tab 212 provides a grasping point which assists itdoffing patient interface 110 in an expeditious fashion in case ofemergency or claustrophobia of patient 101.

FIG. 3 shows a front perspective view of patient interface 110 of anon-invasive ventilation system 160 and illustrates removal/insertion ofan interchangeable patient interface insert 120A, in accordance with anembodiment. As depicted, interchangeable patient interface insert 120Ais in the removed position. Interchangeable patient interface insert120A includes exhaust gas vent ports 123, and is thus designed for usein a vented non-invasive ventilation application. Interchangeablepatient interface insert 120A includes one or more tabs 302 (onevisible) which correspond with, and seat into, slots 303 that aredisposed in the semi-elliptical rim 304 of frame 125. Be applying apinching pressure on grip regions 121-1 and 121-2 (as illustrated byarrows 301), interchangeable patient interface insert 120A can becompressed slightly so that tabs 302 can be seated into slots 303 andinterchangeable patient interface insert 120A can be removably coupledwith frame 125. Reversal of the installation process allows for theremoval of interchangeable patient interface insert 120A.

FIG. 4 shows a front perspective view of patient interface 110 of anon-invasive ventilation system 100 and illustrates an interchangeablepatient interface insert 120B which includes a self-sealing access port401, in accordance with an embodiment. Self-sealing access port 401 mayhave one or more slits or openings through which a tube, such as tube403 may be sealably inserted through interchangeable patient interfaceinsert 120B. As depicted in FIG. 4, self-sealing access port 401comprises one or more slits 402. In some embodiments, as depicted, slits402 may intersect at right angles in the shape of a plus sign.Self-sealing access port 401 provides an opening through which a medicalprofessional can perform procedures such as a bronchoscopy, as it givesaccess for a bronchoscope or other tubing or medical devices/instrumentswhich may be inserted into the oral or nasal cavities of the patient.This allows for insertion of tubes/devices/instruments and performanceof some medical procedures without removing patient interface 110.Instead of doffing patient interface 110 to insert a tube or perform aprocedure, interchangeable patient interface insert 120B can beinstalled (if not already installed) and the procedure can beconducted/tubing inserted through interchangeable patient interfaceinsert 120B. This allows insertion of some tubing and performance ofsome medical procedures, which involve oral or nasal passages, whilestill performing noninvasive ventilation. For example, interchangeablepatient interface insert 120B allows for bronchoscopy to be performed ona sicker ventilated patient, which such a procedure could not otherwisebe performed on, without removing the ventilation. Additionally, tube403 or other device/instrument can be left in place within self-sealingaccess port 401. In some embodiments, self-sealing access port 401 issized, shaped, and configured such that it can couple with a nebulizer,metered dose inhaler, or other therapeutic device or drug deliverydevice, so that that flow from the attached device is directed towards amouth and/or nose of patient 101.

FIG. 5 shows a front perspective view of patient interface 110 of anon-invasive ventilation system 100 and illustrates an interchangeablepatient interface insert 120C which includes a breath sampling port 501,in accordance with an embodiment. As illustrated, interchangeablepatient interface insert 120C does not include the exhaust gas ventports that were included on interchangeable patient interface insert120A and interchangeable patient interface insert 120B. In oneembodiment, this can be because exhaust gas vent ports are disposedelsewhere in patient interface 110. In another embodiment, this isbecause interchangeable patient interface insert 120C is designed foruse with non-vented non-invasive ventilation in which fresh respiratorygas for inhalation is supplied by one limb (e.g., limb 143) and exhaustgas (exhaled breath and unused respiratory gases) is expelled frompatient interface and collected via another limb (e.g., limb 144).Interchangeable patient interface insert 120C includes a breath samplingport 501 to which a breath sampling line 546 may be coupled in order tocapture a sample of exhaled breath from within patient interface 110.Breath sampling line 546 may then couple a captured exhaled breathsample to a carbon dioxide analyzer or other analyzer.

In one embodiment, a slight concavity is defined on the interior portionof interchangeable patient interface insert 120C to form a breath scoop502. Breath scoop 502 is designed so that it is positioned in a regionroughly centered on the upper lip of patient 101 so that it can brieflycapture exhaled breath in a location where it can not be quickly washedaway by a cross-flow between limbs 143 and 144. In other embodiments,instead of being a simple concavity defined on the interior side ofinterchangeable patient interface insert 120C, breath scoop 502 may be aseparate structure, coupled in approximately the same location on theinterior side of interchangeable patient interface insert 120C. Inembodiments which include breath scoop 502, breath sampling port 501sealably couples breath sampling line 546 with breath scoop 502. Breathsampling line 546 operates to couple a captured exhaled breath sample toa carbon dioxide analyzer or other analyzer. Techniques for conductingbreath sampling will be discussed further in a separate section herein.

FIG. 6 shows a front perspective view of patient interface 110 of anon-invasive ventilation system 100 and illustrates a self-sealinggastric tube insertion region 630 disposed within or coupled with facialskin interface 130, in accordance with an embodiment. In FIG. 6, limbs143 and 144 are shown swiveled downward such that that drape down towardthe chest of patient 101. This swiveling allows for the freshrespiratory gas to be provided from the front side of patient 101instead of from the rear/overhead of patient 101. This provides anoption for patient comfort.

As depicted in FIG. 6, a gastric tube 647 has been inserted through aself-sealing an opening 632 defined in gastric tube insertion region630, near the left cheek of patient 101. Gastric tube 647 may be aventing tube, feeding tube, or the like, and may be orogastric ornasogastric. A breath sampling tube or other tube may be inserted in asimilar manner to that of tube 647. In one embodiment, where facial skininterface 130 includes a plurality of flexible bladder sections orcorrugations, insertion region 630 may be a gap between two of theflexible bladders or corrugations which provides an opening 632 forinsertion of tube 647. Herein, a corrugation is a series of convolutionsthat define peaks and valleys in the sealing material, and which canflexibly expand and contract by expanding and contracting thecorrugations. Air pressure supplied by ventilator 160 may inflate thebladders and cause them to seal about tube 647 inserted in a gap thatexists between the bladders. The bladders then transfer the securingforce (provided from head strap system 111 to frame 125) around theinserted tube 647 such that the tube is not driven into the facial skinof patient 101 to create a pressure point. In another embodiment, asdepicted, patient interface 110, includes an arched portion/bridge 631,which provides a rigid or semi-rigid structure to shield tube 647 andopening 632 from the restraining forces which are normally transferredto facial skin interface 130 from head strap system 111, and then fromfacial skin interface 130 to the facial skin of patient 101. Thisprevents this restraining force from causing a pressure point bycompressing tube 647 into the skin of patient 101. In one embodiment, acushioning material 633, such as foam, silicone, or TPE surroundsopening 632 and provides a sealing function for self-sealing about tube647 when inserted in opening 632, sealing opening 632 when tube 647 isnot inserted in opening 632, and sealing to the facial skin of patient101.

In one embodiment, all or part of insertion region 630, opening 632,cushioning material 633, and/or bridge 631 is/are configured tobreakaway facial skin interface 130. That is, one or more of theseportions may be removably coupled with facial skin interface 130. Byconstructing one or more of portions 631, 632, and/or 633 such that theymay be broken away from the rest of patient interface 110, the remainderof patient interface 110 can be removed/doffed from patient 101 withoutremoving tube 647 from patient 101 as would typically be required iftube 647 was inserted through some other opening in a conventionalmask/patient interface. In a similar, when tube insertion region 630 isa gap between a pair of bladders or corrugations, tube 647 can beslipped from between the gap and can remain inserted in patient 101while patient interface 110 is removed/doffed.

FIG. 7 shows a front perspective view of a doffed patient interface 110of a non-invasive ventilation system 100, in accordance with anembodiment, and also illustrates an interchangeable patient interfaceinsert 120D which includes built-in filter media 123A, in accordancewith an embodiment. FIG. 7 illustrates the manner in which thesemi-rigid structure of head strap system 111 retains the general shapeof a helmet, even in a doffed configuration.

In one embodiment, filter media 123A can be used in conjunction with orin place or exhaust gas vent ports 123 which have been depictedelsewhere herein. Typically, exhaust gas vent ports 123 are open to theatmosphere. This allows blowout of exhaled gases into the atmosphere,which may be undesirable or even dangerous to a care giver in somepatient care circumstances. Instead of open vent holes, in oneembodiment, filter media 123A is included or alternatively utilized.Filter media 123A provides a controlled pressure drop in addition tofiltering contagions from exhaled gases as the exhaled gases passthrough. In some embodiments, the filter media 123A can simultaneouslyfilter and vent, thus eliminating the need have separate vent holes.Media such as, but not limited to, filter cloth (e.g., cotton,polyester, or bamboo) or open cell foam may be utilized to form filtermedia 123A. A variety of factors including one or more of composition,thickness, surface area, and porosity of the media of filter media 123Acan be selected, in some embodiments, to both filter contagions andprovide a designated and intentional flow/leak rate to control internalpressure of patient interface 110. In one embodiment, interchangeablepatient interface insert 120D can be removed and replaced with a newinterchangeable patient interface insert 120D when filter media 123Abecomes clogged, soiled, or has surpassed its recommended replacementinterval. In another embodiment, filter media 123A is, itself,replaceable.

In the enlarged view afforded by FIG. 7, a plurality of bladders 736 arevisible which are disposed in compliant nose bridge seal 135. Bladders736 may be filled with air, gas, or liquid upon manufacture of patientinterface 110, in one embodiment. In another embodiment, freshrespiratory gas flow may be utilized (selectively in some embodiments),to inflate bladders 736. Although not illustrated in FIG. 7, in someembodiments, such bladders are also disposed around selected portions orthe entirety of the periphery of facial skin interface 130.

FIG. 7 also illustrates, fasteners 726 (726-1, 726-2, 726-3, 726-4) towhich side straps 112 (112-1, 112-2, 112-3, 112-4) may be buckled orotherwise fastened. In some embodiments, fasteners 726 are permanentlycoupled or removably coupled (i.e., snapped) into positioning tracks 727(727-1, 727-2) along which the position of a fastener 726 may beadjusted. When snap type fasteners 726 are utilized, unsnapping one ormore fasteners 726 provides a means for quick disconnect of side straps112, which allows patient interface 110 to quickly doffed. Slideadjustment allows for the positioning of fasteners 726 and helps adjustfasteners 726 to divert securing force way from compliant nose bridgeseal 135 and the bridge of the nose of patient 101. Additionally,positioning tracks 727 allow adjustment of the pitch and of patientinterface 110 with respect to the face of patient 101.

In some embodiments hook and loop or similar type of fastening may beutilized to secure a side strap 112 or other component. For example,regions 715 (715-1, 715-2, 715-3) illustrate regions where either hookmaterial or loop material may be disposed such that it may be mated withits complimentary hook/loop component disposed on the end portion of aside strap 112 or on a positioning sleeve 748 associated with a tube orother component. When hook and loop type (or similar) fastening isutilized to secure ends of side straps 112, a means for quickly doffingpatient interface is provided by undoing the hook and loop fastening.

In some embodiments, a side strap 112 may change colors or change fromopaque to somewhat translucent, transparent in response to a level offorce induced stress on the strap which is indicative of a level offorce or strap tightening that is considered to be so tight as to causenecrosis if not loosened. For example, an opaque side strap 112 of anycolor may stretch slightly and become translucent or transparent enoughthat a color change is noticeable in response to the stress of the sidestrap being stretched into an over tight state. Similarly, in someembodiments, an opaque side strap 112 of any color may stretch slightlyand become translucent or transparent enough that that an embeddedcolored thread (e.g., a red thread) becomes visibly exposed in responseto the stress of the side strap being stretched into an over tightstate. An example of such an embedded colored thread 712 is shown FIG. 7as being visible on the rear (patient facing) side of side strap 112-4at all times. In various embodiments, embedded thread 712 would onlybecome visibly exposed on the opposite, non-patient facing side of sidestrap 712-4 in response to over tightening of side strap 112-4. It isappreciated that some or all of side straps 112 may include such a colorchanging and/or embedded thread feature to indicate over tightenedconditions. In some embodiments, embedded thread 712 may be embeddedsuch that it is not visible at all, even on the non-patient facing sideof a side strap 712, until the side strap 712 becomes stretched into anover tightened state.

Orifices 722 (722-1, 722-2) are openings disposed, in one embodiment, inframe 125. Limb 143 is illustrated as being sealably coupled withrespiratory gas delivery orifice 722-1 which provides an entry port forfresh respiratory gas from ventilator 160. Similarly, limb 144 isillustrated as being sealably coupled with respiratory gas deliveryorifice 722-2 which provides a second entry port for fresh respiratorygas from ventilator 160 in a vented configuration. In a non-ventedconfiguration, limb 143 or 144 may be used to transport exhaust gasesaway from patient interface 110. In such a non-vented embodiment,orifice 722-2 may then comprise an exhaust gas orifice.

FIG. 8A shows a front perspective view of a patient interface 110A of anon-invasive ventilation system 100 configured with a zygomatic facialinterface 831 and illustrating an interchangeable patient interfaceinsert 120E which includes an aviator style fresh respiratory gasinterface 822, in accordance with an embodiment. By aviator style, whatis meant is that the fresh respiratory gases enter the patient interfaceat approximately a midline position on the front of the patientinterface rather than from one or both lateral sides of the patientinterface.

In FIG. 8A, an alternative, aviator style, vented non-invasiveventilation breathing circuit 840 is illustrated. Breathing circuit 840,in some embodiments, comprises respiratory gas supply tube 841, swivelconnector pieces 842A and 842B, limb 843, anti-asphyxia valve 845, andaviator style fresh respiratory gas interface 822. Anti-asphyxia valve845 operates in the same manner as the previously describedanti-asphyxia valve 745. Interchangeable patient interface insert 120Eis removable/replaceable by compressing grip regions 121-1 and 121-2toward one another. In one embodiment, interchangeable patient interfaceinsert 120E, anti-asphyxia valve 845, limb 843, and swivel connectorpiece 843A are coupled together and supplied as a singleremovable/replaceable unit. Limb 843 couples with respiratory gas supplytube 841 via a torque relieving swivel coupling provided by swivelconnector pieces 842A and 842B which form an omni-directional swivel torelieve torque and prevent kinking and twisting of breathing circuit840. Respiratory gas supply tube 841 couples with ventilator 160 (notvisible in FIG. 8A) in a similar manner as previously described forrespiratory gas tube 141. In one embodiment, gas supply tube 841 maysimilarly utilize a “smart connection” to ventilator 160. Ribs 848configured into limb 843 and/or ribs 849 configured into gas supply line841 provide for torque relief and flexibility, which facilitate patientcomfort and ease of movement while patient interface 110A is donned. Insome embodiments, swivel portions 842A and 842B may be omitted and gassupply tube 841 and limb 843 may be a continuous piece of flexibletubing.

The zygomatic arch is a bony structure, but it also typically has athicker layer of fatty tissue than the bridge of the nose, which isgenerally thin-skinned and has little in the way of cushioning. Becauseof the thin-skin on the bridge of the nose pressure points on the bridgeof the nose quickly disrupt blood flow and create necrosis. Zygomaticfacial interface 831 provides wing like extensions (831-1 and 831-2) offacial skin interface 130 which transfer securing forces of patientinterface 110 to the zygomatic arch areas (cheek bones) of patient 101and also spread the securing forces over a larger surface area of facialskin that other facial skin interfaces illustrated herein. By spreadingsecuring forces to the zygomatic arch, over a larger facial skin surfacearea, and away from the bridge of the nose, zygomatic facial interface831 further reduces the securing force (if any) which is transferred tonose bridge seal 135. Zygomatic facial interface 831 spreads securingforces over a larger surface area of facial skin, and onto zygomaticarch structure. In one embodiment, either or both of facial skininterface 130 and zygomatic facial interface 831 may incorporate aplurality of structural features such as corrugations, ridges, orbladders 836. One of the major differences between a corrugation/ridgeand a bladder is internal, as a bladder may be adjustably filled with agas or fluid, while a corrugation/ridge cannot. Even though designed tobe inflatable filled, a bladder may still have a bumpy exteriorappearance which makes it look similar to and in some respects functionsimilar to a corrugation/ridge. In one embodiment, bladders 836 aresimilar in structure and function to bladders 736 and provide cushioningand allow for some flexibility and movement of patient interface 110Awhile still maintaining an intact facial seal with patient 101.

In one embodiment, patient interface 110A also includes an extended chinportion 832. Oral-nasal masks are intended to capture both the mouth andnose. Extended chin portion 832 helps keep the patient's mouth closed inan oral mask or an oral-nasal mask. This can increase patient comfort.In one embodiment, extended chin portion 832 may include a bellowsfeature (not visible) that expands/contracts in response to movement ofthe chin of patient 101. This allows patient 101 to slightly openhis/her mouth or extend his/her chin without compromising the seal ofpatient interface 110A and allowing respiratory gas to uncontrollablyleak.

In FIG. 8A, side straps such as 112-2 couple with fasteners such asfastener 826. As depicted, fastener 826 is permanently or removablycoupled into a track 827 along which it may be positioned.Slide-to-release mechanism 828 is utilized to lock fastener 826 in adesired position within track 827 or to unlock fastener 826 so that itmay be slidably positioned in track 827. It is noted that in FIGS. 7 and8, strap positioning features are located near the face of patient 101so that they are easily accessible for adjustment by patient 101 or by acare giver.

Although zygomatic facial interface 831, extended chin portion 832,slide-to release-mechanism 828, and interchangeable patient interfaceinsert 120E are illustrated together in FIG. 8A, these features may beutilized separately. For example, zygomatic facial interface 831 can beincorporated into patient interface 110 which is illustrated in FIGS.1-7. Similarly, an aviator style fresh respiratory gas interface 822 maybe utilized in patient interface 110A which does not include zygomaticfacial interface 831.

FIG. 8B is an aviator style patient interface similar to FIG. 8A in allregards (wherein like numerals refer to like components) except that aninterchangeable patient interface insert 120F with an aviator stylefresh respiratory gas interface 822B has replaced interchangeablepatient interface insert 120E and aviator style fresh respiratory gasinterface 822. As can be seen patient interface 120F includesanti-asphyxia valve 845B. As illustrated in FIG. 8B, aviator style freshrespiratory gas interface 822 utilizes an alternative breathing circuit840B which comprises a ribbed respiratory gas supply tube 841 thatconnects directly gas interface 822B without the use of an elbow, andwhich, in some embodiments, does not include a swivel connector piece.

Section 1: Adjusting a Ventilation Mask

Mask 110 includes a sealing portion (e.g., compliant nose bridge seal135 and/or facial skin interface 130). In various embodiments, thesealing portion includes bladders, as described above. For example,compliant nose bridge seal 135 includes bladders 736 and facial skininterface 130 includes bladders 836. In one embodiment, bladders 736extend substantially along the entire length of compliant nose bridgeseal 135. Similarly, in another embodiment, bladders 836 extendsubstantially along the entire length of facial skin interface 130.

In various embodiments, mask 110 is adjusted by fluidly adjusting thebladders (e.g., bladders 736 and 836). In particular, mask 110 isadjusted by inflating the bladders by gas, air, or liquid or anycombination thereof. Also, mask 110 is adjusted by deflating thebladders.

In one embodiment, the bladders are fluidly connected to ventilator 160.For example, each bladder is fluidly connected to ventilator 160 via atube. The tube may be similar to line 546 or tube 647. In such anembodiment, each bladder is fluidly separate from one another and eachbladder is fluidly connected to ventilator 160.

Alternatively, two or more bladders (e.g., adjacent bladders ornon-adjacent bladders) may be fluidly connected to one another. As such,the fluidly connected bladders are fluidly separate from other bladdersor other fluidly connected bladders.

In another embodiment, the bladders are fluidly connected to aninflation source. Such as, but not limited to, a pressure tank.

Mask 110 may be adjusted for a variety of reasons. For example, mask 110may be adjusted in response to a detected unintentional leak.

FIG. 9 depicts an embodiment of a method 900 for adjusting a ventilationmask.

At 910 of method 900, a ventilative state of mask 110 is measured. It isunderstood that mask 110 is placed over a nose and/or mouth of apatient, wherein a sealing portion of mask 110 is for establishing afluid seal between mask 110 and the patient, and wherein the sealingportion comprises a plurality of bladders.

It is also understood that “ventilative state,” used herein, is anystate of system 100 that is measurable and facilitates in determiningwhether or not there is an unintentional leak between mask 110 andpatient 101. For example, a ventilative state can be, but is not limitedto, pressure, airflow, etc.

In one embodiment, at 912, airflow is measured. In another embodiment,at 914, pressure is measured.

In various examples, ventilative states (e.g., airflow, pressure) ofnon-invasive ventilation system 100 are measured. The ventilative statescan be measured by ventilator 160 or other measuring devices.

The measuring can occur by obtaining information of ventilative statesat various locations within system 100. For example, ventilative statescan be measured at mask 110, at breathing circuit 140 and/or ventilator160.

At 920, an unintentional leak of the fluid seal is determined based on ameasured change of the ventilative state. For example, if the measuredpressure and/or airflow in system 100 falls outside of a prescribed orexpected range, then it is determined that there is an unintentionalleak of the fluid seal. An unintentional leak between mask 110 andpatient 101 may occur due to a variety of reasons (e.g., patient mayaccidentally bump mask 110, patient 101 may move mask 110, etc.). As aresult, a ventilative state of system 100 may change.

At 930, a bladder is adjusted to seal the unintentional leak. Forexample, at least one bladder (e.g., at least one of bladders 736 or836) is adjusted. In particular, if there is a gap (e.g., unintentionalleak) between a bladder and patient 101, then the bladder can beadjusted (e.g., inflated) to seal the gap.

In one embodiment, at 931, a bladder is automatically adjusted to sealthe unintentional leak. For instance, in response to measured change inthe ventilative state (e.g., lower pressure) which is indicative of anunintentional leak between mask 110 and patient 101, a bladder isautomatically inflated (e.g., by ventilator 160) to facilitate insealing the unintentional leak. Alternatively, a bladder is manuallyadjusted.

In another embodiment, at 932, bladders are sequentially adjusted. Forexample, in response to a measured change in the ventilative stateoutside an expected or prescribed range, a first bladder is inflated. Ifthe ventilative state still remains outside and expected or prescribedrange, another bladder is inflated, such as an adjacent bladder to thefirst bladder, and so on, until the ventilate state returns to theexpected range and thus the unintentional leak is sealed. Alternatively,a bladder inflated subsequent the first inflated bladder, is notadjacent to the first bladder.

In a further embodiment, at 933, bladders are automatically adjustedaccording to a pre-defined pattern. For example, the inflation ofbladders can initiate at an arbitrary first bladder and continueclockwise or counterclockwise from the first bladder, until theunintentional leak is sealed. In another example, a first bladder,located at a position with a highest probability of unintentionalleakage, is initially automatically adjusted. A second bladder, locatedat a position with a second highest probability of unintentionalleakage, is subsequently adjusted, and so on, until the unintentionalleak is sealed.

In another embodiment, at 934, a bladder is adjusted such that ameasured ventilative state returns to a prescribed ventilative state.For example, in response to a ventilative state falling out of aprescribed or expected range, a bladder is adjusted to stop theunintentional leak. As a result of adjusting the bladder, theventilative state returns to a prescribed ventilative state in aprescribed ventilative state range which is indicative of a proper sealbetween mask 110 and patient 101.

In one embodiment, at 935, more than one bladder is simultaneouslyadjusted. For example, all of the bladders disposed in compliant nosebridge seal 135 are simultaneously adjusted. In another embodiment, allof the bladders disposed on pressure points of patient 101 aresimultaneously adjusted.

Moreover, mask 110 may be adjusted to decrease necrosis.

FIG. 10 depicts an embodiment of a method 1000 for adjusting aventilation mask to decrease necrosis.

At 1010 of method 1000, mask 110 is fluidly sealed to a patient 101,wherein the mask comprises a plurality of bladders (e.g., bladders 736and 836) in physical contact with the patient.

At 1020, a bladder is adjusted to decrease necrosis. For example, abladder(s) is adjusted to decrease pressure at a pressure point. Itshould be appreciated that a bladder(s) can be adjusted to decreasenecrosis similarly to bladders being adjusted as described in method900.

In one embodiment, at 1022, a bladder is adjusted (e.g., deflated) todecrease pressure on a pressure point of the patient.

In another embodiment, at 1024, inflate a bladder of the plurality ofbladders to decrease necrosis. For example, bladders surrounding apressure point are inflated to decrease necrosis.

In a further embodiment, at 1026, a bladder is deflated to decreasenecrosis. For example, a bladder disposed on a pressure point isdeflated to decrease necrosis.

In one embodiment, at 1028, a bladder(s) is automatically adjusted todecrease necrosis. For example, after a predetermined amount of time, abladder(s) located on or about a pressure point are automaticallyadjusted to decrease necrosis.

Section 2: Corrugated Flexible Seal of a Ventilation Mask

Mask 110 includes a sealing portion (e.g., compliant nose bridge seal135 and/or facial skin interface 130). In various embodiments, thesealing portion is a corrugated flexible seal. For example, the sealingportion includes bladders 736 and 836 (also referred to as corrugationsor ridges). The ridges are disposed along the corrugated flexible sealand configured for physical contact with patient 101.

In general, the corrugated flexible seal (in particular, the ridges ofthe corrugated flexible seal) allows for some flexibility and movementof patient interface 110 while still maintaining an intact facial sealwith patient 101.

In one embodiment, corrugated flexible seal is configured to establish afluid seal over the nose of patient 101. For example, a fluid sealoccurs between ridges 736 of compliant nose bridge seal 135 and the nosebridge of patient 101 (see FIG. 7). With respect to ridges 736, theirlength, depth, and width (frequency) may vary in some portions of thecompliant nose bridge.

In another embodiment, the corrugated flexible seal is configured toestablish a fluid seal around the nose and/or mouth of patient 101. Forexample, a fluid seal occurs around the nose and/or mouth of patient 101by ridges 736 of compliant nose bridge seal 135 and ridges 836 of facialskin interface 130.

Corrugated flexible seal (in particular, ridges 736 and/or ridges 836)is configured to move or flex in a plurality of axes and/or directions.This allows for flexibility and movement of patient interface 110 whilestill maintaining an intact facial seal.

Ridges 736, as depicted in FIG. 7, extend along the width of compliantnose bridge seal 135. In other words, the length of each ridge extendsin a direction from the tip of the nose towards the eyes of patient 101.Moreover, ridges 736 are disposed along the length of nose bridge seal135.

Ridges 836, as depicted in FIG. 8, extend along the width of facial skininterface 130. Moreover, ridges 836 are disposed along the length offacial skin interface 130 (and zygomatic facial interface 831). Withrespect to ridges 836, their length, depth, and width (frequency) mayvary in some portions of facial skin interface 130 and or zygomaticfacial skin interface 831. Also, in some embodiments, the length ofridges 736 is longer than the length of ridges 836.

In various embodiments, the ridges of the corrugated flexible seal havedifferent shapes. For example, ridges 836 can have different shapes fromone another and/or have different shapes than ridges 736. Elsewhereherein, microgrooves are described. It should be appreciated that ridgesand valleys of corrugations are much larger in depth and width thanmicrogrooves. For example, in some embodiments corrugations are at leastan order of magnitude larger than microgrooves. It is appreciated thatone or more microgrooves may be configured into a corrugation, in someembodiments.

Section 3: Nasal Passage Opener of a Ventilation Mask

In various embodiments, mask 110 includes a nasal passage opener. Thenasal passage opener is configured for facilitating in opening of anasal passage (or nasal valve). The nasal passage opener is disposedover a nasal passage (or nasal valve) of patient 101 when mask 110 issealed on the face of patient 101. Opening up the nasal passages(valves) can assist in decreasing the rate of breathing and/or patienteffort in breathing.

In one embodiment, the nasal passage opener is compliant nose bridgeseal 135. For example, when compliant nose bridge seal 135 is placedover the nasal passage, the shape of compliant nose bridge seal 135assists in opening the nasal passage, such as with an outward springingforce which pulls open the nasal passages. As a result, the nasalpassage is assisted in opening.

In another embodiment, patient interface 110 interacts with and slightlylaterally stretches the cheek skin of patient 101, where the cheek skinis the skin starting at the lateral edges of the nose and extendinglaterally as far as the skin above the zygomatic arches. This lateralstretching of the cheek skin pulls the nasal passages slightly laterallyto a more open state. With reference to FIGS. 1 and 3-7, in someembodiments, the positioning of side straps 112-1 and 112-3 assists inproviding lateral pressure to facial skin interface 130 to effect thelateral stretching of the cheek skin. With reference to FIG. 5A,zygomatic facial interface portions 831-1 and 831-2 and the positioningof side straps 112-1 and 112-3, in some embodiments, act in concert toslightly laterally stretch the cheek skin of patient 101. It should beappreciated that this cheek skin stretching operates in a similarfashion to the Cottle test, which is used to evaluate nasal valvestenosis. As a result of bilateral facial skin stretching the nasalpassage is assisted in opening.

In another embodiment, the nasal passage opener is a fluidly adjustablebladder or bladders (e.g., bladders 736), as described in Section 1. Forexample, bladders 736 are inflated at the nasal passage. The inflationprovides force onto portions of the nasal passage, which may pull thenasal passage into a more open state, such as by adhesively pulling thenasal passages open in certain regions and/or laterally stretching cheekskin of a patient. As a result, the nasal passage is assisted inopening.

In some embodiments, one or more of facial cheek skin stretching may beutilized, a compliant nose bridge seal, and inflatable bladders may beused in combination for opening the nasal passages of patient 101.

In one embodiment, the nasal passage opener is integrated with mask 110.Alternatively, the nasal passage opener is removable from mask 110.

FIG. 11 depicts an embodiment of a method for assisting in opening anasal passage.

At 1110, a ventilation mask is sealed over a face of a patient, whereinthe ventilation mask is disposed over a nasal passage. For example, mask110 is sealed over the face of patient 101, wherein mask 110 is disposedover a nasal passage.

At 1120, nasal passage is assisted in opening by the ventilation maskdisposed over the nasal passage. For example, the nasal passage isassisted in opening by compliant nose bridge seal disposed over thenasal passage and/or by lateral cheek skin stretching provided by mask110.

In one embodiment, at 1122, a cross-sectional area of a nasal passage isincreased. For example, the cross-sectional area of the nasal passage isincreased because of the nasal passage opener.

In another embodiment, at 1124, a bladder is adjusted to assist inopening of the nasal passage. For example, a single bladder is inflatedto urge in the opening of a nasal passage.

In a further embodiment, at 1126, a plurality of bladders is adjusted toassist in opening of the nasal passage. For example, a plurality ofbladders (e.g., bladders 736) are inflated, such that it urges open thenasal passage. As a result, the cross-sectional area of the nasalpassage is increased.

Section 4: A Carbon-Dioxide Sampling Device for Noninvasively MeasuringCarbon Dioxide in Exhaled Breath

With reference now to FIG. 12, in accordance with an embodiment, a frontperspective view 1200 is shown of a non-invasive ventilation patientinterface 110, which is also referred to herein as a mask 110, withcarbon-dioxide sampling device 1201 for non-invasively measuring carbondioxide in exhaled breath. Patient interface 110 includes acarbon-dioxide sampling device 1201, straps 112-1, 112-2 and 112-3, aninhalation gas supply line 144, which is also referred to herein as limb144 of the breathing circuit 140, and an exhalation gas collection line143, which is also referred to herein as limb 143 of the breathingcircuit 140. The inhalation gas supply line may be identified with limb144 of the breathing circuit 140, as previously described; and, theexhalation gas collection line may be identified with limb 143 of thebreathing circuit 140, as previously described; however, theseidentifications of the inhalation gas supply line and the exhalation gascollection line are by way of example, without limitation thereto, asother implementations of the inhalation gas supply line and theexhalation gas collection line are within the spirit and scope ofembodiments described herein. In addition, patient interface 110 mayalso include a y-piece 142, as previously described, which functions asa gas-line coupling.

With further reference to FIG. 12, in accordance with an embodiment, thecarbon-dioxide sampling device 1201 is configured to non-invasivelymeasure carbon dioxide in exhaled breath. The carbon-dioxide samplingdevice 1201 includes a breath-sampling chamber 1210, and acarbon-dioxide collector 502, which is also referred to herein as breathscoop 502. The carbon-dioxide collector 502 may be identified with thebreath scoop 502, as previously described; however, this identificationof the carbon-dioxide collector 502 is by way of example, withoutlimitation thereto, as other implementations of the carbon-dioxidecollector 502 are within the spirit and scope of embodiments describedherein. The breath-sampling chamber 1210 is configured to be disposedover a patient's mouth and/or nose, and configured to seal with apatient's face preventing unintentional leakage of respiratory gasesfrom the breath-sampling chamber 1210. By way of example withoutlimitation thereto, the breath sampling chamber 1210 includes a frame125, a facial skin interface 130, a compliant nose bridge seal 135, andan interchangeable patient interface insert 120C, which have beenpreviously described. The carbon-dioxide collector 502 is disposed inthe breath-sampling chamber 1210. The carbon-dioxide collector 502 isconfigured to be disposed in proximity to, and outside of, the noseand/or mouth of the patient 101, and to collect a sample of exhaledbreath from the patient 101. The straps 112-1, 112-2 and 112-3 areconfigured to hold the breath-sampling chamber 1210 in place over thepatient's mouth and/or nose, and to apply tension to make a seal with apatient's face preventing unintentional leakage of respiratory gasesfrom the breath-sampling chamber 1210. The inhalation gas supply line144 is coupled with the breath-sampling chamber 1210, and is configuredto transport oxygen gas to the patient 101. The exhalation gascollection line 143 is coupled with the breath-sampling chamber 1210,and is configured to remove exhaled gases from the breath-samplingchamber 1210.

With further reference to FIG. 12, in accordance with an embodiment,patient interface 110 also includes an interchangeable insert 120C thatis disposed at a front of the breath-sampling chamber 1210. Thecarbon-dioxide sampling device 1201 also includes a breath-sampling line546, as previously described. Thus, patient interface 110 also includesa breath-sampling line 546 configured to transport a sample of theexhaled breath from the patient 101 collected by the carbon-dioxidecollector 502. The interchangeable insert 120C includes abreath-sampling port 501 that is configured to couple thebreath-sampling line 546 with the carbon-dioxide collector 502. Thebreath-sampling line 546 is configured to transport a sample of exhaledbreath from the patient 101 collected by the carbon-dioxide collector502. A portion of the breath-sampling line 546 proximate to thebreath-sampling chamber 1210 is securely attached to the breath-samplingchamber 1210, and is configured to prevent accidental interference bythe patient 101 with the breath-sampling line 546. By way of example,the breath-sampling chamber 1210 may be configured as a respirationchamber of a breathing mask 110, without limitation thereto.

With further reference to FIG. 12, in accordance with an embodiment, thecarbon-dioxide sampling device 1201 may also include a carbon-dioxideindicator 1220 that is configured to indicate when a threshold level ofcarbon dioxide is exceeded in the exhaled breath from the patient 101.Thus, patient interface 110 includes the carbon-dioxide indicator 1220that is configured to indicate when a threshold level of carbon dioxideis exceeded in the exhaled breath from the patient 101. Thecarbon-dioxide indicator 1220 includes a visible portion that isconfigured to change an appearance of the visible portion when athreshold level of carbon dioxide is exceeded in the exhaled breath fromthe patient 101. The carbon-dioxide indicator 1220 may also include avisible portion that is configured to change color when a thresholdlevel of carbon dioxide is exceeded in the exhaled breath from thepatient 101. The carbon-dioxide indicator 1220 may be mountedconspicuously on a portion of the carbon-dioxide sampling device 1201 tobe readily observable by an attendant of the patient 101.

With reference now to FIG. 13, in accordance with an embodiment, across-sectional view 1300 is shown of patient interface 110 taken alongline 13-13 of FIG. 12. FIG. 13 illustrates the carbon-dioxide samplingdevice 1201 including the breath-sampling chamber 1210, and acarbon-dioxide collector 502. As shown in FIG. 13, component parts ofthe breath-sampling chamber 1210 are also shown in cross-section, forexample, frame 125, facial skin interface 130, compliant nose bridgeseal 135, and interchangeable patient interface insert 120C, coveringthe patient's mouth and/or nose. Thus, the breath-sampling chamber 1210is configured to be disposed over a patient's mouth and nose, as shown.In other embodiments, a similar breath-sampling chamber may be disposedover only the nose or only the mouth of a patient. The breath-samplingchamber 1210 is also configured to seal with a patient's face preventingunintentional leakage of respiratory gases from the breath-samplingchamber 1210. The carbon-dioxide collector 502 is disposed in thebreath-sampling chamber 1210, and is fluid dynamically isolated fromflow of fresh respiratory gases such that exhaled breath may be capturedtherein and directed toward breath-sampling line 546. The carbon-dioxidecollector 502 is configured to be disposed in proximity to, and outsideof, a respiratory opening (nose, mouth, or nose and mouth) of thepatient 101, and to collect a sample of exhaled breath from the patient101. As shown in FIG. 13, the carbon-dioxide collector 502 includes anupper portion 502-1 of the breath scoop 502, a lower portion 502-2 ofthe breath scoop 502, and a breath-scoop channel 502-3. The upperportion 502-1 of the breath scoop 502 and the lower portion 502-2 of thebreath scoop 502 are designed to capture the patient's breath eitherfrom the nose or the mouth of the patient 101, is indicated by therespective arrows in FIG. 13 directed from the patient's nose and mouth,with substantially no dilution with respiratory gases supplied to thepatient 101. The breath-sampling line 546 is also shown in FIG. 13;unlike other elements of the figure, the breath-sampling line 546 is notshown in cross-section, but rather, lies generally outside of the planeof the figure, for the purpose of facilitating the description. Thecarbon-dioxide collector 502 communicates with the breath-sampling line546 through the breath-sampling port 501. Thus, the carbon-dioxidecollector 502 is configured to collect a sample of the exhaled breathfrom the patient 101 that is substantially undiluted by respiratorygases supplied for the patient's breathing.

With further reference to FIG. 13, in accordance with an embodiment, thecarbon-dioxide sampling device 1201 may further include a carbon-dioxidesensor (not shown) that is configured to sense a level of carbon dioxidein the exhaled breath of the patient 101, and to output a carbon-dioxidesensor signal commensurate with the level of carbon dioxide. In oneembodiment, the carbon-dioxide sensor may be co-located with thecarbon-dioxide collector 502, so that a sensor signal commensurate withthe content of carbon dioxide in the breath of the patient 101 may beobtained as close as possible to the source of exhaled breath, yetnon-invasively. Thus, the carbon-dioxide collector 502 may include thecarbon-dioxide sensor.

With reference now to FIGS. 14 and 15, in accordance with alternativeembodiments, a schematic diagram 1400 is shown of a carbon-dioxideanalyzer 1401 of one embodiment in FIG. 14; and, a schematic diagram1500 is shown of a carbon-dioxide analyzer 1401 of an alternativeembodiment in FIG. 15. The carbon-dioxide sampling device 1201 may alsoinclude the carbon-dioxide analyzer 1401 of either embodiment. As shownin FIG. 14, the carbon-dioxide analyzer 1401 is configured to determine,from a sample of exhaled breath from the patient 101, a measurement ofcarbon-dioxide content in the sample of exhaled breath from the patient101. As shown in the alternative embodiment of FIG. 15, for example, fora carbon-dioxide sensor that may be co-located with the carbon-dioxidecollector 502, the carbon-dioxide analyzer 1401 is configured to converta sensor signal received from the carbon-dioxide sensor into ameasurement of carbon dioxide content in the sample of exhaled breathfrom the patient 101. The carbon dioxide analyzer 1401 also includes acarbon-dioxide analysis protocol executor 1402 to provide an accuratemeasurement of carbon dioxide content in the sample of the exhaledbreath from the patient 101 that is substantially unaffected by dilutionfrom respiratory gases supplied for the patient's breathing. Both thecarbon-dioxide analyzer 1401 and the carbon-dioxide analysis protocolexecutor 1402 may include: hardware, firmware, hardware and software,firmware and software, hardware and firmware, and hardware and firmwareand software, any of which are configured to assist in the analysis ofthe sample of exhaled breath from the patient 101 to obtain ameasurement of carbon dioxide content that is substantially undiluted byrespiratory gases supplied for the patient's breathing. Moreover, thecarbon-dioxide analyzer 1401 and the carbon-dioxide analysis protocolexecutor 1402 may be configured as separate electronic devices that areseparate from any ventilator 160 used to ventilate a patient 101 withrespiratory gases. The carbon-dioxide analyzer 1401 and thecarbon-dioxide analysis protocol executor 1402 may include, by way ofexample without limitation thereto, a computer system.

With reference now to FIG. 16, in accordance with an embodiment, aflowchart 1600 is shown of a method for non-invasively measuring carbondioxide in exhaled breath of a patient. The method includes thefollowing operations. At 1610, a carbon-dioxide collector is disposed inproximity to, and outside of, the nose and mouth of the patient. At1620, a sample of exhaled breath is collected from the patient. Thesample of the exhaled breath from the patient is substantially undilutedby respiratory gases supplied for the patient's breathing, for example,as described above, by means of the breath scoop 520. The method mayfurther include the following operations. At 1630, a level of carbondioxide in the exhaled breath of the patient is sensed with acarbon-dioxide sensor. At 1640, a sensor signal is output that iscommensurate with the level of carbon dioxide. At 1650, the sensorsignal is converted into a measurement of carbon dioxide content in thesample of exhaled breath from the patient with the carbon-dioxideanalyzer. In addition, at 1660, a carbon-dioxide analysis protocol maybe applied to provide an accurate measurement of carbon dioxide contentin the sample of the exhaled breath from the patient that issubstantially unaffected by dilution from respiratory gases supplied forthe patient's breathing.

Section 5: A Carbon-Dioxide Sampling System for Accurately MonitoringCarbon Dioxide in Exhaled Breath

With reference now to FIG. 17, in accordance with an embodiment, aschematic diagram 1700 is shown of a carbon-dioxide sampling system 1701for accurately monitoring carbon dioxide in exhaled breath. Herein,“accurately” refers to measuring carbon dioxide levels closely to theiractual (true) values. The carbon-dioxide sampling system 1701 includes aventilator 160. The ventilator 160 is configured to ventilate a patient101 with respiratory gases. The ventilator 160 includes a carbon-dioxidesampling control unit 160-1, and a carbon-dioxide analyzer 1401.Although similar to the carbon-dioxide analyzer 1401 described above, incontrast with the carbon-dioxide analyzer 1401 described above, thecarbon-dioxide analyzer 1401 is configured as an integral part of theventilator 160, and therefore, is also configured as an integral part ofthe carbon-dioxide sampling system 1701. The carbon-dioxide samplingcontrol unit 160-1 is configured to control the timing of sampling ofcarbon dioxide in the exhaled breath of a patient 101, and to controlthe timing of an analysis of exhaled gases by the carbon-dioxideanalyzer 1401. The carbon-dioxide sampling control unit 160-1 mayinclude: hardware, firmware, hardware and software, firmware andsoftware, hardware and firmware, and hardware and firmware and software,any of which are configured to assist in the sampling of the sample ofexhaled breath from the patient 101 to obtain a measurement of carbondioxide content that is substantially undiluted by respiratory gasessupplied for the patient's breathing. Thus, the carbon-dioxide samplingcontrol unit 160-1 is configured to control collection of a sample ofexhaled breath from the patient 101 that is substantially undiluted byrespiratory gases supplied for the patient's breathing.

With further reference to FIG. 17, in accordance with an embodiment, theventilator 160 further includes a ventilation timing unit 160-2. Theventilation timing unit 160-2 may include: hardware, firmware, hardwareand software, firmware and software, hardware and firmware, and hardwareand firmware and software, any of which are configured to assist inventilating a patient 101 at regular intervals based on measured levelsof carbon dioxide in the breath of the patient 101. The carbon-dioxideanalyzer 1401 is configured to regulate the ventilation timing unit160-2 to ventilate a patient 101 at regular intervals based on measuredlevels of carbon dioxide in the breath of the patient 101. The carbondioxide analyzer 1401 may also include an analysis protocol executor1402 to provide an accurate measurement of carbon dioxide content in thesample of the exhaled breath from the patient 101 that is substantiallyunaffected by dilution from respiratory gases supplied for the patient'sbreathing, as previously described.

With further reference to FIG. 17, in accordance with an embodiment, thecarbon-dioxide sampling system 1701 may also include a breath-samplingchamber 1210. As previously described, the breath-sampling chamber 1210is configured to be disposed over a respiratory opening of a patient(nose, mouth, or nose and mouth), and is configured to seal with apatient's face preventing unintentional leakage of respiratory gasesfrom the chamber. Moreover, the breath-sampling chamber 1210 isconfigured to be coupled to the ventilator 160, as an integral part ofthe carbon-dioxide sampling system 1701. The carbon-dioxide samplingsystem 1701 may further include a carbon-dioxide collector 502, aspreviously described, which is disposed in the breath-sampling chamber1210. The carbon-dioxide sampling system 1701 may further include anexhalation-gas collection line 143, as previously described, coupled tothe breath-sampling chamber 1210 configured to collect exhaled gases ina breath exhaled by the patient 101, and to transport the exhaled gasesto the carbon-dioxide analyzer 1401.

With reference now to FIG. 18, in accordance with an embodiment, a frontperspective view 1800 is shown of patient interface 110 of a combinednon-invasive ventilation patient interface 110 and carbon-dioxidesampling system 1701. The combined interface 110 and system 1701includes patient interface 110, and a carbon-dioxide sampling system1701, as described above in the discussions of FIGS. 9 and 14,respectively. The breath-sampling chamber 1210 includes a respirationchamber of a breathing mask 110. The combined patient interface 110 andcarbon-dioxide sampling system 1701 may further include a separatebreath-sampling line 546 that is configured to transport a sample of theexhaled breath from the patient 101 to the carbon-dioxide analyzer 1401.The combined patient interface 110 and carbon-dioxide sampling system1701 may also include an inhalation gas supply line 144 and anexhalation gas collection line 143. The inhalation gas supply line 144is coupled with the breath-sampling chamber 1210, and is configured totransport oxygen gas to the patient 101. The exhalation gas collectionline 143 is coupled with the breath-sampling chamber 1210, and isconfigured to remove exhaled gases from the breath-sampling chamber1210. In an alternative embodiment, the exhalation gas collection line143 may be configured to transport a sample of the exhaled breath fromthe patient 101 to the carbon-dioxide analyzer 1401, instead of theseparate breath-sampling line 546. The exhalation-gas collection line143 is securely attached to the breath-sampling chamber 1210, and isconfigured to prevent accidental interference by the patient 101 withthe exhalation-gas collection line 143. The combined patient interface110 and carbon-dioxide sampling system 1701 may also include acarbon-dioxide indicator 1220, as previously described in the discussionof FIG. 12. The carbon-dioxide indicator 1220 is configured to indicatewhen a threshold level of carbon dioxide is exceeded in the exhaledbreath from the patient 101. The carbon-dioxide indicator 1220 ismounted conspicuously on a portion of the mask 110 to be readilyobservable by an attendant of the patient 101.

With reference now to FIG. 19, in accordance with an embodiment, aschematic diagram 1900 is shown of the carbon-dioxide analyzer 1401. Thecarbon-dioxide analyzer 1401 may further include a carbon-dioxide sensor1901. The carbon-dioxide sensor 1901 is configured to sense a level ofcarbon dioxide in the exhaled breath of the patient 101, and to output asensor signal commensurate with the level of carbon dioxide. The carbondioxide analyzer 1401 may also include a sensor-signal converter 1902.The sensor-signal converter 1902 may include: hardware, firmware,hardware and software, firmware and software, hardware and firmware, andhardware and firmware and software, any of which are configured toconvert the sensor signal into a measurement of carbon dioxide contentin the sample of the exhaled breath from the patient 101. Thus, thesensor-signal converter 1902 is configured to convert the sensor signalinto a measurement of carbon dioxide content in the sample of theexhaled breath from the patient 101. The carbon-dioxide analyzer 1401may further include an analysis protocol executor 1402. The analysisprotocol executor 1402 is configured to provide an accurate measurementof carbon dioxide content in the sample of the exhaled breath from thepatient 101 that is substantially unaffected by dilution fromrespiratory gases supplied for the patient's breathing, as previouslydescribed. The carbon-dioxide sensor 1901 may include an infra-reddetector 1901-1, and a source of infra-red radiation 1901-2. Theinfra-red detector 1901-1, by way of example, without limitationthereto, may be a semiconductor photo-diode. The infra-red detector1901-1 is configured to measure the absorbance of infra-red radiation ata frequency within an absorption band of carbon dioxide for theinfra-red radiation, and to generate a sensor signal commensurate withthe level of carbon dioxide based on absorbance.

With reference now to FIG. 20, in accordance with an embodiment, aschematic diagram 2000 is shown of a combination 2001 of acarbon-dioxide measurement display 2001-2 and a carbon-dioxidemeasurement recorder 2001-1. The carbon-dioxide measurement recorder2001-1 may be a computer system and/or the memory of a computer system,without limitation thereto. As shown in FIG. 20, the carbon-dioxidemeasurement display 2001-2 may be configured to display data from theventilator 160, for example, such as: respiration rate, indicated by thesinusoidal waveform on the carbon-dioxide measurement display 2001-2;the activity of the ventilator 160 in supplying respiratory gases, forexample, oxygen, to the patient 101, indicated by the square-wavewaveform; and, a textual display of the partial pressure of carbondioxide in exhaled breath, P_(E)CO₂. As shown in FIG. 20, the partialpressure of carbon dioxide in exhaled breath may be displayed as adecimal number in units of pressure, given in units of millimeters ofmercury (mm Hg), without limitation thereto.

With reference now to FIG. 21, in accordance with an embodiment, aflowchart 2100 is shown of a method for accurately monitoring carbondioxide in exhaled breath of a patient. The method includes thefollowing operations. At 2110, a sampling of carbon dioxide in anexhaled breath of a patient is timed with a carbon-dioxide samplingcontrol unit.

At 2120, the timing of an analysis of gases in an exhaled breath of apatient is controlled with a carbon-dioxide analyzer. The carbon-dioxidesampling control unit is configured to control collection of a sample ofthe exhaled breath from the patient that is substantially undiluted byrespiratory gases supplied for the patient's breathing. Therefore, thecollection of the exhaled breath sample may be timed not to coincidewith a time when respiratory gases, for example, oxygen, are beingsupplied to the patient. The method may also include the followingoperation. At 2130, a ventilation timing unit is regulated to ventilatea patient at regular intervals based on measured levels of carbondioxide in the breath of the patient. In addition, at 2140, acarbon-dioxide analysis protocol may be applied to provide an accuratemeasurement of carbon dioxide content in the sample of the exhaledbreath from the patient that is substantially unaffected by dilutionfrom respiratory gases supplied for the patient's breathing.

Section 6: Interchangeable Inserts

Various embodiments provide a ventilation mask with a removable insert.In one embodiment, the front portion of the mask is removable to enableaccess to a respiratory opening region such as either the mouth, noseregion, or both the mouth and nose regions of a patient withoutrequiring removal of the entire mask and strap system. The nose regionwould comprise at least the nasal (nose) opening and may furthercomprise one to several centimeters surrounding the nasal opening. Themouth region would comprise at least the oral (mouth) opening and mayfurther comprise one to several centimeters surrounding the oralopening. This enables quick access to the mouth and/or nose region whilesimultaneously ventilating the patient.

The removable insert enables a caregiver access to the mouth and/noseregion of the patient that would be inaccessible with a conventionalventilation mask on the patient. With a conventional mask, the entiremask and strapping system would need to be removed to gain access to thenose and/or mouth region of the patient. Thus, the removable insert ofsaves considerable time because mask adjustment is significantlyreduced, especially when access to the mouth and/or nose region of thepatient is desired.

The removable insert enables the patient to perform many tasks whilebeing simultaneously ventilated. For example, a patient can eat, takemedication, brush teeth, talk, etc., with the insert removed. It shouldbe appreciated that the patient is still ventilated even with theremovable section of the mask removed from the frame portion.

Referring back to FIG. 1, domed front portion 120 is removable fromframe portion 125 to enable access to the mouth and/or nose region ofthe patient without requiring removal of the frame portion 125 from thepatient. In this embodiment, the mouth and/or nose region of the patientcan be accessed without removing or adjusting strapping system 111.

Referring back to FIG. 3, a front perspective view of patient interface110 of a non-invasive ventilation system 160 is shown and illustratesremoval/insertion of an interchangeable patient interface insert 120A,in accordance with an embodiment. As depicted, interchangeable patientinterface insert 120A is in the removed position to enable access to thenose and/or mouth region of the patient. Interchangeable patientinterface insert 120A includes exhaust gas vent ports 123, and is thusdesigned for use in a vented non-invasive ventilation application.Interchangeable patient interface insert 120A includes one or more tabs302 (one visible) which correspond with, and seat into, slots 303 thatare disposed in the semi-elliptical rim 304 of frame 125. Be applying apinching pressure on grip regions 121-1 and 121-2 (as illustrated byarrows 301), interchangeable patient interface insert 120A can becompressed slightly so that tabs 302 can be seated into slots 303 andinterchangeable patient interface insert 120A can be removably coupledwith frame 125. Reversal of the installation process allows for theremoval of interchangeable patient interface insert 120A.

It is appreciated that when the removable insert 120A is in the removedposition, the patient is still receiving gas flow from limb 143 becausethe airflow enters the frame portion 125 of the mask. The removableinsert enables simultaneous ventilation and access to the mouth and/ornose region of the patient.

In one embodiment, the removable insert includes a graphic or color onthe outside surface (facing away from the patient) so the patient canhave a customized look. For example, a portion of the removable insertmay be opaque or a color such as orange, red, or blue (or configuredwith multiple colors). Some non-limiting examples of a graphic include:a handlebar mustache, stars, a rainbow, a beard, chin whiskers, amonster face, a smiley face, etc. In another embodiment, the insidesurface of the removable insert is scented, such as with cinnamon scent,mint scent, citrus scent, bubble gum scent, or other scent, to provide apleasing scent to the patient while being ventilated. It is appreciatedthat the removable insert 120A may be dosed with medication for acontrolled release to the patient via either a nasal entry or mouthentry.

In another embodiment, therapeutic devices can be incorporated with theremovable insert. For example, a bite plate on the inside surface can beincorporated into the removable insert to function as both a bite plateand a cover for the mask. It is appreciated that any number oftherapeutic devices could be incorporated with insert 120A on the insidesurface (facing patient) and/or on the outside surface (facing away fromthe patient).

The removable insert may also be coated in the inside surface with ananti-fogging layer to reduce fogging on the inside surface. Anti-fogcoating assists in maintaining a transparent surface which allows anunimpeded view of the nose and lips of a patient, so that a caregivermay easily assess the patient without requiring removal of eitherpatient interface 111 or removable insert 120A (or other removableinsert 120 which is coated with anti-fog coating on its interiorsurface).

Referring now to FIG. 22, a method 2200 for accessing a mouth and/ornose region of a ventilated patient is provided. In one embodiment,access to the mouth and/or nose region of a patient is provided whilesimultaneously ventilating the patient. With method 2200 of, mouthand/or nose region access can be achieved without requiring removal ofthe mask or mask strapping system from the patient. At 2202, 2200includes ventilating the patient.

At 2204, method 2200 includes accessing a frame portion of a masksurrounding the mouth and/or nose region of the patient wherein theframe region is coupled with a semi-rigid retention strap formaintaining positive pressure between the frame portion and the mouthregion of the patient.

At 2206, 2200 includes removing a removable insert that is configured tophysically attach and detach from the frame portion without requiringremoval of said frame portion or said retention strap from said patientwhile simultaneously ventilating the patient.

After the removable insert is removed, access to the nose and/or mouthregion of the patient is achieved while simultaneously ventilating thepatient.

It is appreciated that the replaceable insert can be used for any numberof functions. For example, the removable insert can be selected toprovide a therapeutic function to the patient such as a bite block, drugdelivery, oral and/or nasal care, feeding, suction, etc. The removableinserts can be configured with any number of ports, filters, drugdelivery systems, etc., and can also be colored or include a graphicdesign. The removable insert enables access to the nose and/or mouthregion of the patient while not interrupting ventilation of the patientor requiring removal of the mask from the patient.

Section 7: Lateral Gas Line Configuration

Various embodiments described herein include a lateral configuration ofgas delivery limbs coupled with a ventilation mask. The lateralconfiguration can be used in single limb applications as well asmultiple limb applications. However, a dual configuration usingbilateral limbs facilitates a cross flow of air across a respiratoryopening region (i.e., at least the nose opening and/or mouth opening) ofa patient which purges dead space and thus improves ventilation of thepatient. In one embodiment, the lateral gas line configuration enablesventilation of a patient even with a removable front portion of the maskin the removed position. This lateral configuration of the gas deliverylimbs facilitates access to the nose and/or mouth region of the patientwhile simultaneously ventilating the patient. While only bilateral limbsare depicted (limb on each lateral side of a patient interface and thuson each side of a patient's face when donned), it is appreciated thatonly one lateral limb, on either lateral side of the patient interface,may be utilized in some embodiments.

The lateral gas line configurations described herein are also configuredto improve comfort and stability of the mask on the patient. Forexample, in one embodiment, a gas limb is coupled with the mask via aswivel connection which enables the gas limb to swivel with respect tothe mask. The swivel mount(s) between the gas limb and the mask frameenables free movement of the gas limb(s) without imparting torque on themask itself. By reducing the torque on the mask frame, even pressure canbe achieved between the mask and the patient, thus improving patientcare and comfort.

Referring back to FIG. 1, a bilateral gas line configuration is shown.Breathing circuit 140 includes limbs 143 and 144 which are shown to bedisposed in a lateral configuration with respect to the temporal regionof the patient. The limb (143, 144) may be coupled to the frame portion125 via a swivel port connection which enables the limb to rotate withrespect to the frame portion 125 without imparting torque to the frameportion of the mask. It is appreciated that the swivel connectionbetween the frame portion 125 and the limb enables the limbs to be movedfrom a lateral position to a front position shown in FIG. 2 where thelimb 143 is shown to be rotated to the front of the patient. In thisembodiment, the limbs 143, 144 are positioned such that the patient canlay on the side of their head without having a breathing tube in the wayor interfering with ventilation. In one embodiment, limbs 143 and 144are coupled at Y connector 142 where the Y connector 142 includes one ormore swivel connectors.

FIG. 3 shows a bilateral gas line configuration with breathing limbs 143and 144 positioned laterally with respect to the patient's head. In thisembodiment, a front removable insert 120A is shown in the removedposition. With the lateral gas line configuration described herein,ventilation can occur with the front removable insert in the removedposition because the gas flow is configured to flow across a respiratoryopening region (i.e., at least the nose opening and/or mouth opening) ofthe patient. With the removable insert in the removed position, gas flowcan still be delivered to the patient. The described lateral gas lineconfigurations facilitate simultaneous ventilation of a patient whileenabling access to the mouth and/or nose region of the patient.

Referring back to FIG. 7, one or more limb of breathing circuit 140 maybe coupled with strap system 111. For example, region 715 may include afastener to removably couple limb 143 to side strap 112 of strap system111. In this embodiment, at least one portion of the breathing circuit140 is configured in a parallel relationship with a strap 112 of strapsystem 111. It is appreciated that orifices 722 may be configured asswivel connections that enable swivel movement of the connected deviceor tube.

In one embodiment, gas delivery orifices 722 are non-concentric withrespiratory opening regions (mouth opening region and nasal openingregions) of a patient. In other words, gas delivery orifice(s) 722 areshifted laterally, away from the midline, with respect to any of theseopenings. Furthermore, gas delivery orifice 722-1 and 722-2 are shiftedlaterally with respect to front portion 120; that is, they do not definean opening through any part of front portion 120.

Section 8: Quick Donning Headgear

Various embodiments include a quick donning headgear for patientventilation. The quick donning headgear described herein enables quickand intuitive application and removal of the headgear so as to improvepatient care and reduce time spent donning and removing the headgearfrom the patient.

In some embodiments, the headgear apparatus includes a semi-rigid strapsystem that enables intuitive application to the patient. The semi-rigidstraps maintain a head-shape of the strap system even when not in use.The semi-rigid design enables faster donning of the headgear as opposedto conventional strap systems because the straps are alreadypre-arranged in the proper configuration prior to use, thus reducing theeffort and/or time involved in applying and/or removing the device. Thesemi-rigid shape also requires less adjustment compared to conventionalstrapping systems because it is already in the shape of a human head. Itis appreciated that any portion(s) of head strap 111 may include aridged or semi-rigid material. It is also appreciated that thesemi-rigid material may be flexible.

Referring back to FIG. 1, head strap 111 includes side straps 112(112-1, 112-2, 112-3 and 112-4 (not visible in FIG. 1, but illustratedin FIG. 7). In one embodiment, any portion of straps 112 could be formedof a ridged or semi-rigid material and/or may have elastic properties.In one embodiment, straps 112 retain a head like shape when not appliedto a patient.

In one embodiment, straps 112 may include a portion that is semi-rigidand also flexible so that the head shape can be expanded for largerpatients without requiring adjustment of straps 112 at the frame portion125. The head-shape of the strap system 111 also enables greatersecuring force distribution between the patient's skin and the maskstructure because less adjustment is required. Depending on theconfiguration (nasal, oral, or oral/nasal) of a patient interface 110which is utilized with strap system 111, the head-shape of the strapsystem 111 evenly distributes the force around either the patient'smouth region, nose region, or both the mouth region and nose region toreduce possible skin irritations and improve patient comfort.

Referring back to FIG. 7, in some embodiments, one or more of sidestraps 112 may be configured to change color, such as from opaque totranslucent or from opaque to transparent, or from a lighter shade to adarker shade, in response to stress being applied to the side strap 112which is indicative of over tightening of the side strap 112. Similarly,in some embodiments, one or more of side straps 112 may be configured tochange color, such as from opaque to translucent or from opaque totransparent, or from a lighter shade to a darker shade such that anembedded colored thread 712 becomes visibly exposed via the non-patientfacing side of a side strap 112 in response to stress being applied tothe side strap 112 which is indicative of over tightening of the sidestrap 112.

Referring back to FIG. 2, the quick donning headgear system 111 mayinclude a quick release tab 212 that can be used for rapid removal ofthe patient interface 110 from the patient in the event of an emergency.The quick release tab 112 can also be used in donning of the headgear toas to adjust the position of the strap system 111 on the patient's head.

The semi-rigid construction of head strap system 111 provides someamount of inherent rigidity so that when it is in storage, it can becollapsed; but when it's removed from collapsed storage, it easily andnaturally returns to a general head shaped structure, so that it isvisibly obvious how to position and install head strap system 111 onpatient 101 when donning patient interface 110. In this manner, there isno need to sort out where the front, back, top, or bottom is located. Inone embodiment, patient interface 110 is packaged with head strap system111 already pre-attached with frame 125, so that when unpackaged thesemi-rigid structure of head strap system 111 causes it to look somewhatlike a helmet that can just be pulled quickly over the head and facearea of patient 101, much like putting on a catcher's mask.

Section 9: Smart Connections

Various embodiments include “smart connectors” for use with patientventilators. “Smart” refers to a feature that is user friendly and aidsin or prevents misconnections with a ventilator that would configureventilation improperly for a patient. The smart connectors enable properconfiguration of a ventilation system and also can be used to determinecontinuity of the system. For purposes of the present description, theterm “continuity” is used to describe the physical continuity of theventilation system, meaning that correct parts are used and that thecorrect parts are properly connected and functioning properly.

In one embodiment, physical similarities and dissimilarities of variousventilation components are used to enable compatible parts to coupletogether while preventing dissimilar or non-compatible parts from beingused. In this way, non-compatible parts are not physically able tocouple with non-compatible parts, thus preventing an improperconfiguration of the system from being used with a patient. Moreover,with respect to the proper connection point, there may be only oneorientation in which a smart connector can be coupled to the connectionpoint on the ventilator (in order to prevent inadvertent misconnection).This may be accomplished via design feature (shape), labeling, colorcoding, or combination of these features. In another embodiment,identifiers such as color, barcode, RFID, etc. are used to distinguishsimilar and dissimilar parts.

For example, in one embodiment, different classes of parts (e.g., forvarious patient populations, flow rated, type of ventilation, etc.) canbe configured to have unique connector ends that only enable compatibleparts to mate with. The special physical configuration of various partsalso prevents non-compatible parts to be used.

In another embodiment, the ventilation parts can be color coded. In thisembodiment, parts with the same color can be considered compatible andcan be used together. Parts with different colors can be considerednon-compatible and should not be used together. When looking at aventilation configuration, a part with a different color from the restis easily identified as non-compatible and should be replaced with acompatible part with the same color as the rest. In one embodiment,different ventilation methods (e.g., single or dual limb) have differentcolors indicating different uses. In another embodiment, differentcolored parts are used to differentiate parts for different patientpopulations.

In another embodiment, parts with different colors can be compatible. Inthis embodiment, semi-transparent parts of various colors can be used tocreate “good” colors and “bad colors.” For example, a yellow part can becombined with a blue colored part to create a “good” color of greenwhile a blue part combined with a red part create a “bad” color ofpurple. It is appreciated that any number of colors, patterns, picturesor any other unique markings could be used in accordance with theembodiments described herein to distinguish ventilation parts.

In another embodiment, various parts of the ventilation system caninclude a machine readable code or identifier that enables tracking andmonitoring of the parts of the ventilation system. For example, in oneembodiment, one or more parts of the ventilation system include abarcode or RFID tag that enables identification of the parts and enableddetermination of system configuration. In this embodiment, partcompatibility can be verified and system configuration can be verified.In one embodiment, the ventilator includes a reader that can read theidentifier associated with the parts to determine compatibility and/orsystem configuration.

In another embodiment, one or more parts of the ventilation systeminclude an electrical lead for enabling a continuity check of one ormore portions of the ventilation system. When various parts with thewire lead are coupled, a continuous wire lead is established between theparts. A signal can be passed through the lead to check the lead iscontinuous. In this embodiment, inadvertent disconnection between any ofthe parts can be detected, thus improving patient care and ventilationfunctions.

Referring to FIG. 23, a ventilator 160 is shown comprising a signalreader 2300 and a configuration determiner 2305. The breathing circuit140 includes a wire lead 2304 for enabling the signal reader 2300 todetermine continuity of at least a portion of breathing circuit 140. Inone embodiment, the signal reader 2300 provides a signal to theelectrical lead 2304 and determines continuity based on the signalreturned.

In one embodiment, the signal can also be used to determine aconfiguration of the ventilation system. For example, various parts canhave electrical components that enable the signal reader to identifywhich parts are in the system and can determine their configurationbased on sending and receiving a signal over electrical leas 2304.

In another embodiment, one or more parts of the ventilation systeminclude a machine readable identifier such as an RFID or barcode. Inthis embodiment, the signal reader 2300 is configured to read thecorresponding barcode and/or RFID to perform system configuration andcontinuity checks. It is appreciated that in one embodiment, theconfiguration determiner 2305 is also configured to determineconfiguration information based on the RFID signal and/or barcodeinformation.

Referring to FIG. 24, a method 2400 for checking continuity of abreathing circuit is provided. At 2402, a signal is provided to a firstend of an electrical lead of a breathing circuit. In one embodiment, oneor more parts of the ventilation system include a wire lead that can beused to transmit a signal to determine continuity of that part and/orany parts coupled with that part.

At 2404, the signal is transmitted to a second end of the electricallead. Provided the electrical lead is continuous, at 2406, the signal isreceived at a second end of the electrical lead and at 2408, it can bedetermined that the breathing circuit is continuous based on thereceived signal.

Provided the electrical lead is non-continuous, at 2410, the signal isnot received at a second end of the electrical lead and at 2412, it canbe determined that the breathing circuit is non-continuous based on thereceived signal. At this point, an alert can be generated to signal thebreathing circuit is discontinuous and may need to be reconfigured.

Referring now to FIG. 25, a method 2500 for determining configuration ofa breathing circuit is provided. At 2502, a signal is provided at afirst end of an electrical lead of a breathing circuit. At 2504, thesignal is transmitted to a second end of the electrical lead. At 2506,the signal is received at the second end of the electrical lead. At2508, configuration of the breathing circuit is determined based on thesignal received.

In one embodiment, as the signal is transmitted through the electricallead, any number of modifications to the signal could be performed byany number of components in the system. The modification of the signalenables the signal reader 2300 of FIG. 23 to determine configuration ofthe breathing circuit. For example, a “smart” connector may include amicrochip that enables access to real-time data associated with the partor the ventilation system as a whole.

Section 10: Tube Placement in Non-Invasive Ventilation

FIGS. 26A-26C illustrate detail views of a self-sealing tube insertionregion 630, according to various embodiments. Some embodiments of aself-sealing tube insertion region 630 were previously described inconjunction with FIG. 6, and FIGS. 26A-26C further extrapolate on thoseembodiments.

As illustrated, in FIG. 26A, bridge 631 and cushioning material 633(which defines and includes self-sealing tube opening 632 may beremovably coupled with facial skin interface 130, in one embodiment. Forexample, bridge 631 may be coupled to facial skin interface 130 via anadhesive with a low shear force which may be used one or more timeswithout exhausting its adhesion abilities. Additionally oralternatively, bridge 631 may be positioned and then held in place (asdepicted in FIG. 6) by the securing force which is supplied by headstrap system 111. By being removably coupled with facial skin interface130, a portion of the tube insertion region can be decoupled frompatient interface 110 when patient interface 110 is doffed. Tube 647 maybe an orogastric tube, nasogastric tube, or carbon dioxide samplingtube. If tube 647 is orogastrically or nasogastrically inserted intopatient 101, then this portion of tube insertion region can be decoupledfrom patient interface 110 when patient interface 110 is doffed. Thisallows the tube 647 to remain in place, without being removed or havingits function interfered with in anyway by the doffing of patientinterface 110.

As depicted in FIG. 26A self-sealing tube insertion region 630 can becoupled or decoupled with facial skin interface 130 and self-seals abouttube 647 when tube 647 is disposed in opening 632, between the facialskin of patient 101 facial skin interface 130. As previously described,bridge 634 diverts this securing force around tube 647 while tube 647 isinserted in opening 632. Cushioning material 633 may be foam, silicone,TPE, or other cushioning material. In one embodiment, bridge 631 andcushioning material 633 may be the same material but in differentthicknesses or configurations to provide different structuralfunctionality (e.g., bridging versus cushioning/sealing). Cushioningmaterial 633 seals opening 632 when tube 647 is not present expanding tofill opening 632 which may be a piercing through cushioning material633. Similarly, cushioning material 633 conforms to tube 647, wheninserted into opening 632, and self-seals around tube 647 to preventunintentional leakage of gases from patient interface 110.

As depicted in FIG. 26B, in one embodiment, opening 632 may be a slit632A defined within cushioning material 633. Tube 647 may be anorogastric tube, a nasogastric tube, a carbon dioxide sampling tube, arespiratory gas sampling tube, or other type of tube. Tube 647 can beinserted and removed from slit 632A without affecting positioning orfunction of tube 647. For example, if tube 647 is orogastrically ornasogastrically inserted into patient 101, tube 647 may be inserted orremoved into slit 632A without removing tube 647 or disturbing thefunction of tube 647. Slit 632A comprises a self-sealing tube receivingopening, in that cushioning material 633 expands to removably seal abouttube 647 when tube 647 is disposed in slit 632A. Similarly, cushioningmaterial expands to seal slit 632A closed when tube 647 is not present.In some embodiments a removable, reusable (e.g., low shear force, lowtack) adhesive is applied within slit 632A to facilitate sealing of slit632A when no tube is present in slit 632A and to facilitate removablesealing of slit 632A about a tube 647 (when inserted).

As depicted in FIG. 26C, in one embodiment, opening 632 may be a gap632B defined in a bladder feature 836 of facial skin interface 130. Gap632B functions in a similar fashion to slit 632A. Gap 632B may bedefined in a single bladder 836 or in a space between a pair of adjacentbladders 836. For example, if tube 647 is orogastrically ornasogastrically inserted into patient 101, tube 647 may be inserted orremoved into gap 632B without removing tube 647 or disturbing thefunction of tube 647. Gap 632B comprises a self-sealing tube receivingopening, in that bladder feature 836 removably seals about tube 647 whentube 647 is disposed in gap 632B. This sealing can be due to one or morefactors such as compressing of bladder feature 836 by the securing forcesupplied by head strap system 111 and/or by inflation of bladder(s) 836by inhalation gases present within patient interface 110 and suppliedfrom ventilator 160 (or by other source of gas or fluid). For example,the bladder(s) 836 may be sealably inflated around tube 647. Similarly,bladder feature 836 seals gap 632B closed when tube 647 is not present.In some embodiments a removable, reusable (e.g., low shear force, lowtack) adhesive is applied within gap 632B to facilitate sealing of gap632B when no tube is present in gap 632B and to facilitate removablesealing of gap 632B about a tube 647 (when inserted). As can be seen,tube 647 can be received in and removed from gap 632B independently ofthe donning and doffing of patient interface 110. When tube 647 isinserted within gap 632B, bladder feature 836 diverts the securing force(supplied by head strap system 111) around tube 647 such that tube 647is not pressed against the facial skin of patient 101 to form a pressurepoint.

Section 11: Non-Invasive Ventilation Exhaust Gas Venting

As described previously with reference to FIG. 7, in one embodiment,filter media 123A can be used in conjunction with or in place or exhaustgas vent ports 123 which have been depicted elsewhere herein. Typically,exhaust gas vent ports 123 are open to the atmosphere. Instead of openvent holes, in one embodiment, filter media 123A is included in additionto vent ports 123 or alternatively utilized to replace vent ports 123.Filter media 123A filters contagions (e.g., bacteria, viruses, drugs (inparticular aerosolized or nebulized drags), and/or chemicals) from theexhaust gas which is exhausted through filter media 123A. The exhaustedgas may comprise exhaled breath, excess fresh respiratory gas, or acombination thereof. In addition to filtering, filter media 123Adiffuses the gases that are exhausted there through. Filter media can becomposed of any known type of respiratory gas filter media, including,but not limited to, paper, activated carbon, synthetic woven fiber(e.g., polyester, Gortex® or similar expanded polytetrafluoroethylene(ePTFE)), open cell foam, glass fiber, natural woven fiber (e.g.,bamboo, cotton), or combination thereof.

In some embodiments, filter media 123A provides a controlled pressuredrop in addition to filtering contagions from exhaled gases as theexhaled gases pass through. This controls an expulsion flow of exhaledbreath and can also control an intentional leak rate of freshrespiratory gases from within patient interface 110. Such intentionalleak rate control can manage the pressure of fresh respiratory gaseswithin patient interface 110 such that a desired pressure range ofcontinuous positive airway pressure is achieved. A variety of factorsincluding one or more of composition, thickness, layers, surface area,and porosity of the media of filter media 123A can be selected, in someembodiments, to either filter contagions, provide a designatedflow/intentional leak rate to control internal pressure of patientinterface 110, or both.

In some embodiments, the filter media 123A can simultaneously filter andvent, thus eliminating the need have separate vent holes. In oneembodiment, interchangeable patient interface insert 120D can be removedand replaced with a new interchangeable patient interface insert 120Dwhen filter media 123A becomes clogged, soiled, or has surpassed itsrecommended replacement interval. In another embodiment, filter media123A is, itself, replaceable.

In some embodiments, filter media 123A may be imbued with one or moresubstances. For example in one embodiment, filter media 123A may beimbued with a fragrance such as cinnamon, mint, peppermint, spearmint,wintergreen, citrus, fruit, bubblegum or the like in order to mask odorsof exhaust gases which are not eliminated by filter media 123A. In oneembodiment, filter media 123A, may be imbued with a desiccant (e.g.,silica, activated charcoal, or the like) in order to assist incontrolling moisture level on the interior of patient interface 110 toreduce fogging and/or to improve patient comfort, and in order tomaintain filter media 123A in a dry state which is can kill viruses andis non-conducive to formation of funguses. Along these lines,transparent portions of domed front portion 120 or similarinterchangeable insert 120D (and the like) may have interior portionscoated with an anti-fog coating to prevent fogging and to maintaintransparency both for patient comfort and so that medical personnel mayeasily view inside of patient interface 110. In one embodiment, filtermedia 123A is imbued with an antibacterial, antimicrobial, and/orantifungal substance (e.g., silver, an antibiotic, etc.)

FIG. 27 illustrates a replaceable filter cartridge 2724, in accordancewith some embodiment. Filter cartridge 2724 is shown in an uninstalledstate. Arrow 2750 illustrates where filter cartridge 2724 may be snapfit or otherwise coupled with interchangeable insert 120D, or a similarinterchangeable or non-interchangeable domed front portion 120. This isone mechanism for changing for replacing filter media 123 when cloggedor past a time of suggested usability. In other embodiments, filtermedia 123A is an integral portion of interchangeable insert 120D (ratherthan a replaceable cartridge), and the entirety of interchangeableinsert 120D is removed and replaced in order to replace filter media123. In some embodiments a larger portion of interchangeable insert 120Dmay be composed of filter media 123 than depicted in FIG. 27 or otherfigures herein. For example, in some embodiments up to the entirevisible exterior surface of interchangeable insert 120D may be composedof one or some combination of filter materials.

Section 12: Non-Invasive Ventilation Facial Skin Protection

Many features for skin protection have been discussed previously herein.Additional features which may be used alone or in combination with thepreviously discussed skin protection features (or with other skinprotection features that are described in Section 13) include featureswhich eliminate fluid via wicking and/or purging, and features whichutilize an imbued substance to actively soothe/protect the facial skinin one or more areas which receive contact from a patient interface as aresult of non-invasive ventilation.

FIG. 28 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal 135 and a facial skin interface 130,according to an embodiment. As illustrated by enlarged detail 2801, theskin contacting portion of facial skin interface 130 is configured witha plurality of micro-grooves 2825 which provide small passagewaysbetween skin contacting peaks 2824 which allow air flow. In oneembodiment, micro-grooves 2825 may be 0.075 inches or narrower in width,in another embodiment some of micro-grooves 2825 may be 0.050 inches ornarrower in width. In one embodiment, some or all of microgrooves 2825may be between 0.075 and 0.005 inches in width. When patient interface110 is donned and coupled with ventilator 160, pressurized freshrespiratory gas flows through micro-grooves 2825 in a controlled andintentional leak as illustrated by gas flow path 2826. This controlledand intentional leak facilitates a controlled purging of moisture byboth forcing moisture out through micro-grooves 2825, and by evaporatingmoisture. This controlled leak assists in purging moisture and thuspreventing accumulation of fluids (e.g., sweat, condensation, or thelike) and/or eliminating fluids from within facial interface 110 (theportion which covers nose and/or mouth openings when donned) and frombetween facial skin interface 130 and the facial skin of patient 101that is in contact with facial skin interface 130 when patient interface110 is donned. In one embodiment, micro-grooves 2825 may be aremovable/replaceable component which is removably coupled with facialskin interface 130. Thus when micro-grooves 2825 get clogged or exceed arecommended service time, this replaceable component can be replaced.

As illustrated in FIG. 28 by enlarged detail 2833, the skin contactingportion of compliant nose bridge seal 135 may additionally oralternatively be configured with a plurality of micro-grooves 2835 whichprovide small passageways between skin contacting peaks 2834 which allowair flow. In one embodiment, micro-grooves 2835 may be 0.075 inches ornarrower in width, in another embodiment some of micro-grooves 2835 maybe 0.050 inches or narrower in width. In one embodiment, some or all ofmicrogrooves 2835 may be between 0.075 and 0.005 inches in width. Whenpatient interface 110 is donned and coupled with ventilator 160,pressurized fresh respiratory gas flows through micro-grooves 2835 in acontrolled and intentional leak as illustrated by gas flow path 2836.This controlled and intentional leak facilitates a controlled purging ofmoisture by both forcing moisture out through micro-grooves 2835, and byevaporating moisture. This controlled and intentional leak assists inpurging moisture and thus preventing accumulation of fluids (e.g.,sweat, condensation, or the like) and/or eliminating fluids from withinfacial interface 110 (the portion which covers nose and/or mouthopenings when donned) and from between compliant nose bridge seal 135and the facial skin of patient 101 that is in contact with compliantnose bridge seal 135 when patient interface 110 is donned. In oneembodiment, micro-grooves 2835 may be a removable/replaceable componentwhich is removably coupled with compliant nose bridge seal 135. Thuswhen micro-grooves 2835 get clogged or exceed a recommended servicetime, this replaceable component can be replaced.

As illustrated in FIG. 28, in one embodiment, facial skin interface 130additionally or alternatively includes an extended chin portion 832,which may include a chin bellows 2850 and/or a jaw bellows 2855. Chinbellows 2850 and jaw bellows 2855 each include a plurality of bellowsformed of a cushioning material such as silicone. In variousembodiments, chin bellows 2850 and/or jaw bellows 2855 may be formed ofthe same material as facial skin interface 130. Chin bellows 2850expands and contracts in response to up and down movement of the chin ofpatient 101, such as when patient 101 opens and closes his/her mouthduring speaking. Jaw bellows 2850 is inboard of the sealing surface offacial skin interface 130, and expands and contracts in response to up,down, and side-to-side movement of the jaw of patient 101, such as whenpatient 101 opens and closes his/her mouth during speaking, yawning, orfor a medical procedure accomplished through an open front portion ofpatient interface 110. The expansion and contraction provided by chinbellows 2850 and/or jaw bellows 2855 allows for some linear and/orside-to-side movement of the mouth, chin and/or jaw of patient 101 whilemaintaining contact between facial skin interface 130 and the face ofpatient 101. This can increase patient comfort and decrease the need toconstantly manually adjust patient interface 101 in response tounintentional leaks caused by movement of the jaw and/or chin of patient101. Additionally, a caregiver or patient may access an oral or nasalopening or region through a removable insert 120 and jostle or moveportions of patient interface 110 without causing unintentional leaks.This is because the accordion like bellows features of chin bellows 2850and/or jaw bellows 2855 allow for some flexing movement such that outerportions of patient interface 110 while the facial skin contactingportions remain undisturbed or relatively undisturbed in their seatingagainst the facial skin of the patient.

FIG. 29 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal 135 and a facial skin interface 130,according to an embodiment. As illustrated by enlarged detail 2901, theskin contacting portion of facial skin interface 130 comprises a porousmaterial 2925 (e.g., open cell foam) which provides a plurality of smallopenings and small passageways in/near its surface, due to the porosity.When patient interface 110 is donned and coupled with ventilator 160,pressurized fresh respiratory gas flows through porous material 2925 ina controlled and intentional leak as illustrated by gas flow path 2926.This controlled and intentional leak facilitates a controlled purging ofmoisture by both forcing moisture out through the pores of porousmaterial 2925, and by evaporating moisture. This controlled andintentional leak assists in purging moisture and thus preventingaccumulation of fluids (e.g., sweat, condensation, or the like) and/oreliminating fluids from within facial interface 110 (the portion whichcovers nose and/or mouth openings when donned) and from between facialskin interface 130 and the facial skin of patient 101 that is in contactwith facial skin interface 130 when patient interface 110 is donned. Inone embodiment, porous material 2925 may be a removable/replaceablecomponent which is removably coupled with facial skin interface 130.Thus when porous material 2925 gets clogged or exceeds a recommendedservice time, this replaceable component can be replaced.

As illustrated in FIG. 29, the skin contacting portion of compliant nosebridge seal 135 may additionally or alternatively be configured with asimilar porous material 2935 which provide small passageways andopenings in/near its surface, due to the porosity. When patientinterface 110 is donned and coupled with ventilator 160, pressurizedfresh respiratory gas flows through pores of porous material 2935 in acontrolled and intentional leak as illustrated by gas flow path 2936.This controlled and intentional leak facilitates a controlled purging ofmoisture by both forcing moisture out through pores of porous material2935, and by evaporating moisture. This controlled leak assists inpurging moisture and thus preventing accumulation of fluids (e.g.,sweat, condensation, or the like) and/or eliminating fluids from withinfacial interface 110 (the portion which covers nose and/or mouthopenings when donned) and from between compliant nose bridge seal 135and the facial skin of patient 101 that is in contact with compliantnose bridge seal 135 when patient interface 110 is donned. In oneembodiment, porous material 2935 may be a removable/replaceablecomponent which is removably coupled with compliant nose bridge seal135. Thus when porous material 2935 gets clogged or exceeds arecommended service time, this replaceable component can be replaced.

As illustrated in FIG. 29, in one embodiment, facial skin interface 130additionally or alternatively includes an extended chin portion 832,which may include a chin bellows 2850 and/or may include a jaw bellows2850.

FIG. 30 illustrates a perspective view of the skin contacting portion ofa compliant nose bridge seal 135 and a facial skin interface 130,according to an embodiment. As illustrated by enlarged detail 3001, theskin contacting portion of facial skin interface 130 is comprises awicking material 3025 (e.g., a woven cloth such as cotton, wool, bamboo,polyester micro fiber, or other known wicking materials) which providesa surface that naturally wicks fluids and moisture. In some embodiments,the wicking surface of facial skin interface 130 may be textured. Thiswicking property assists in wicking moisture and thus preventingaccumulation of fluids (e.g., sweat, condensation, or the like) and/oreliminating fluids from within facial interface 110 (the portion whichcovers nose and/or mouth openings when donned) and from between facialskin interface 130 and the facial skin of patient 101 that is in contactwith facial skin interface 130 when patient interface 110 is donned. Inone embodiment, wicking material 3025 may be a removable/replaceablecomponent which is removably coupled with facial skin interface 130.Thus when wicking material 3025 gets clogged, saturated, or exceeds arecommended service time; this replaceable component can be replaced. Insome embodiments, the wicking material 3024 may be porous enough toexhibit purging properties as well as wicking properties. Arrow 3026illustrates the direction of gas flow through a porous wicking material3024.

As illustrated in FIG. 30, the skin contacting portion of compliant nosebridge seal 135 may additionally or alternatively be configured with asimilar wicking material 3035 (e.g., a woven cloth such as cotton, wool,bamboo, polyester micro fiber, or other known wicking materials) whichprovides a textured surface that naturally wicks fluids and moisture.Wicking material 3035 provides a textured wicking surface forinterfacing with nasal skin of patient 101 when patient interface 110 isdonned. This wicking property assists in wicking moisture and thuspreventing accumulation of fluids (e.g., sweat, condensation, or thelike) and/or eliminating fluids from within facial interface 110 (theportion which covers nose and/or mouth openings when donned) and frombetween compliant nose bridge seal 135 and the facial skin of patient101 that is in contact with compliant nose bridge seal 135 when patientinterface 110 is donned. In one embodiment, wicking material 3035 may bea removable/replaceable component which is removably coupled withcompliant nose bridge seal 135. Thus when wicking material 3035 getsclogged, saturated, or exceeds a recommended service time; thisreplaceable component can be replaced. In some embodiments, wickingmaterial 3034 may be porous enough to exhibit purging properties as wellas wicking properties. Arrow 3036 illustrates the direction of gas flowthrough a porous wicking material 3034.

As illustrated in FIG. 30, in one embodiment, facial skin interface 130additionally or alternatively includes an extended chin portion 832,which may include a chin bellows 2850 and/or may include a jaw bellows2850.

In some embodiments, all or a portion of facial skin interface 130,compliant nose bridge seal 135, micro-grooves 2825, porous material3925, and/or wicking material 3025 is imbued with one or more substanceswhich actively soothe/protect the facial skin in one or more areas whichreceive contact from a patient interface as a result of non-invasiveventilation. Such substances may include one or more of an antibacterialsubstance (e.g., tricolsan, silver, or other known substances withantibacterial and/or antifungal properties), an emollient, and/or avasodilator. An imbued antibacterial can prevent/destroy a bacteriaand/or a fungus which may inhabit the environment where facial skin of apatient contacts or is enclosed by patient interface 110. An imbuedemollient softens and moisturizes the skin, and can thus assist inprevention of chafing, rashes, and skin necrosis caused by prolongedcontact between patient interface 110 and facial skin of patient 101. Aimbued vasodilator dilates (widens) blood vessels by relaxing smoothmuscle cells of the vessel walls, thus improving blood flow in facialskin. Such improved blood flow can assists in preventing necrosis thatcan occur if patient interface 110 causes a pressure point on facialskin of patient 101, or can prolong the amount of time that patientinterface 110 can be worn without damaging facial skin of patient 101.

In some or all embodiments, all or portions of facial skin interface 130may be treated with a low shear force adhesive such that a slighttackiness (similar to that of a Post-It® note) is achieved. Thistackiness improves mask stability, thus reducing the amount of slidingand decreasing irritation to the skin caused by constant sliding andshifting.

Section 13: Non-Invasive Ventilation Facial Skin Protection

Referring again to FIG. 8A, a patient interface which includes azygomatic facial interface 831 (831-1, 831-2) is illustrate, accordingto an embodiment. In one embodiment, zygomatic facial interface is anextension of or is coupled with facial skin interface 130. In oneembodiment, first zygomatic interface portion 831-1 sealably interfaceswith facial skin covering a left zygomatic arch region of patient 101,while second zygomatic interface portion sealably interfaces with facialskin covering a right zygomatic arch region of patient 101. In responseto application of a securing force for securing patient interface 110and facial skin interface 130 over a mouth and/or nose opening of saidpatient, first portion 831-1 and second portion 831-2 spreading thesecuring force away from a nasal bridge of patient 101 and onto to theleft and right zygomatic arch regions of patient 101. The securing forceis supplied by a head strap system, such as or similar to head strapsystem 111, which supplies the securing force in response to donning ofpatient interface 110. In one embodiment, zygomatic facial interface 831may comprise a plurality of bladders 836, which may be inflated with afluid or may be inflated with fresh respiratory gas supplied byventilator 160. In some embodiments, zygomatic facial interface 831includes a moisture purging feature (e.g., micro-grooves 2825 and/orporous material 3025) which contacts facial skin of patient 101 andwhich allows/facilitates a controlled and intentional leak of freshrespiratory gas between the moisture purging feature and the facial skinof patient 101. In one embodiment, zygomatic facial interface 831includes a wicking feature (e.g., wicking material 3025) which contactsfacial skin of patient 101 and wicks fluid from the contacted facialskin. In one embodiment, a skin contacting region of zygomatic facialinterface 831 is imbued with at least one of an emollient, anantibacterial, and a vasodilator. In one embodiment, a skin contactingregion of zygomatic facial interface is imbued with two or more of anemollient, an antibacterial, and a vasodilator.

In various embodiments, a patient interface 110 which utilizes zygomaticfacial interface 831 may include extended chin portion 832 (which mayfurther include chin bellows 2850). It is appreciated that otherfeatures described herein may be included, in various combinations witha patient interface 110 which includes zygomatic facial skin interface831. For example, in some embodiments, a patient interface 110 whichutilizes zygomatic facial interface 831 may include compliant nosebridge seal 135, corrugations, jaw bellows, tube insertion region,microgrooves, porous material, wicking material, and nasal passageopening features, among other features.

Although features have been illustrated and described herein as appliedto oral/nasal patient interfaces which seal about the mouth and noseopenings of a patient, it is appreciated that the features describedherein may also be applied to patient interfaces which seal only about amouth opening of a patient or only about a nose opening of a patient.

The foregoing descriptions of specific embodiments have been presentedfor purposes of illustration and description. They are not intended tobe exhaustive or to limit the presented technology to the precise formsdisclosed, and obviously many modifications and variations are possiblein light of the above teaching. The figures and embodiments were chosenand described in order to best explain the principles of the presentedtechnology and its practical application, to thereby enable othersskilled in the art to best utilize the presented technology and variousembodiments with various modifications as are suited to the particularuse contemplated. While the subject matter has been described inparticular embodiments, it should be appreciated that the subject mattershould not be construed as limited by such embodiments, but ratherconstrued according to the following claims.

The invention claimed is:
 1. A mask for patient ventilation comprising:a frame portion for surrounding a respiratory opening region of apatient; a front portion removably coupled with said frame portion andconfigured for covering said respiratory opening region, wherein accessto said respiratory opening region is unobstructed upon removal of saidfront portion; a retention strap for maintaining positive pressurebetween the frame portion and said patient; a gas delivery orificedirectly coupled with and on a first side of said frame portion andconfigured such that said gas delivery orifice is lateral to said frontportion; and a gas evacuation orifice directly coupled with and on asecond side, opposite the first side, of said frame portion lateral tosaid front portion; wherein, when the mask is positioned on the patient,the gas delivery orifice directs a cross-flow of gas from the first sideof the frame to the second side of the frame across the respiratoryopening region of the patient, and wherein removal of the front portionfrom the frame portion does not separate the gas delivery orifice andgas evacuation orifice from the frame, such that the cross-flow of gasacross the respiratory opening region of the patient, and through thegas evacuation orifice, is maintained when the front portion is removedfrom the frame portion.
 2. The mask of claim 1 further comprising: a gaslimb coupled with said gas delivery orifice for providing gas flow tosaid respiratory opening region of said patient.
 3. The mask of claim 2wherein said gas limb is adapted to be disposed laterally with respectto a temporal region on the head of the patient.
 4. The mask of claim 3,wherein said gas limb comprises a plurality of tubes.
 5. The mask ofclaim 2 wherein said gas limb is coupled with said retention strap suchthat it is adapted to be proximate a temporal region of said patient. 6.The mask of claim 2 wherein said gas limb is swivelably coupled withsaid gas delivery orifice.
 7. The mask of claim 2 wherein said gas limbis coupled with said frame portion such that said positive pressurearound said frame portion is evenly distributed on said patient.
 8. Themask of claim 2 wherein said gas delivery orifice is configured toprovide said gas flow across said respiratory opening region.
 9. Themask of claim 1, wherein said frame portion comprises an openingconfigured to accept said front portion and to allow access to the noseand mouth.
 10. The mask of claim 1, wherein: said frame portioncomprises an opening configured to accept said front portion; and saidopening is adapted to be disposed directly over the mouth such that aninstrument can be inserted through said opening into an oral passage ofthe patient.
 11. The mask of claim 10, wherein said front portioncomprises an access port configured such that an instrument can beinserted through said access port into the oral passage.
 12. The mask ofclaim 1, wherein: said frame portion comprises an opening configured toaccept said front portion; and said opening is adapted to be disposeddirectly over the mouth and nose such that an instrument can be insertedthrough said opening into at least one of an oral passage and a nasalpassage of the patient.
 13. The mask of claim 12, wherein said frontportion comprises an access port configured such that an instrument canbe inserted through said access port into at least one of the oral andnasal passages.
 14. The mask of claim 1, wherein removal of the frontportion from the frame portion does not separate the gas deliveryorifice from the respiratory opening region.
 15. A mask for patientventilation comprising: a frame portion for surrounding a respiratoryopening region of a patient; a front portion removably coupled with saidframe portion and configured for covering said respiratory openingregion; a retention strap for maintaining positive pressure between theframe portion and said patient; a plurality of gas delivery orificesdirectly coupled with and on a first side of said frame portion andconfigured such that that each of said plurality of gas deliveryorifices is lateral to said front portion; a gas evacuation orificedirectly coupled with and on a second side, opposite the first side, ofsaid frame portion lateral to said front portion; wherein, when the maskis positioned on the patient, the plurality of gas delivery orificesdirects a cross-flow of gas from the first side of the frame to thesecond side of the frame across the respiratory opening region of thepatient, and wherein removal of the front portion from the frame portionprovides unobstructed access to said respiratory opening region and doesnot separate the gas delivery orifice and gas evacuation orifice fromthe frame, such that the cross-flow of gas is maintained when the frontportion is removed from the frame portion.
 16. The mask of claim 15further comprising: a gas limb coupled with at least one of said gasdelivery orifices for providing gas flow to said respiratory openingregion of said patient.
 17. The mask of claim 16, wherein said gas limbcomprises a plurality of tubes.
 18. The mask of claim 16 wherein saidgas limb is adapted to be disposed laterally with respect to a temporalregion on the head of the patient.
 19. The mask of claim 16 wherein saidgas limb is parallel with at least a portion of said retention strap.20. The mask of claim 16 wherein said gas limb is coupled with at leasta portion of said retention strap.
 21. The mask of claim 16 wherein saidgas limb is swivelably coupled with said at least one gas deliveryorifice.
 22. The mask of claim 16 wherein said gas limb is coupled withsaid frame portion such that said positive pressure between said frameportion and said patient is evenly distributed.
 23. The mask of claim 16wherein at least one of said gas delivery orifices is configured toprovide said gas flow across said respiratory opening region.
 24. A maskfor patient ventilation comprising: a frame portion for surrounding anose and mouth of a patient; a front removable portion coupled with saidframe portion and configured for covering said nose and mouth, whereinaccess to said nose and mouth is unobstructed upon removal of said frontportion; a retention strap for maintaining positive pressure between theframe portion and the patient; a gas delivery orifice coupled with andon a first side of said frame portion and configured such that said gasdelivery orifice is lateral to said front removable portion; a gasevacuation orifice directly coupled with and on a second side, oppositethe first side, of said frame portion lateral to said front removableportion; wherein, when the mask is positioned on the patient, the gasdelivery orifice directs a cross-flow of gas from the first side of theframe to the second side of the frame across the nose and mouth of thepatient, and wherein removal of the front portion from the frame portionprovides unobstructed access to said nose and mouth and does notseparate the gas delivery orifice and gas evacuation orifice from theframe.
 25. The mask of claim 24 further comprising: a gas limb coupledwith said gas delivery orifice for providing gas flow to said nose andmouth of said patient when said front removable portion is removed fromsaid frame portion.
 26. The mask of claim 25 wherein said gas limbcomprises a plurality of tubes.
 27. The mask of claim 25 wherein saidgas limb is adapted to be disposed laterally with respect to a temporalregion on the head of the patient.
 28. The mask of claim 25 wherein saidgas limb is coupled with said retention strap such that it is adapted tobe proximate a temporal region of said patient.
 29. The mask of claim 25wherein said gas limb is swivelably coupled with said gas deliveryorifice.
 30. The mask of claim 25 wherein said gas limb is coupled withsaid frame portion such that said positive pressure around said frameportion is evenly distributed on said patient.
 31. The mask of claim 25wherein said gas delivery orifice is configured to provide said gas flowacross said nose and mouth of said patient when said front removableportion is removed from said frame portion.
 32. A mask for patientventilation comprising: a frame portion for surrounding a nose and mouthof a patient; a front portion removably coupled with said frame portionand configured for covering said nose and mouth, wherein access to saidnose and mouth is unobstructed upon removal of said front portion; aretention strap for maintaining positive pressure between the frameportion and the patient; a first gas delivery limb coupled with a firstside region of said frame portion; and a second gas limb coupled with asecond side region of said frame portion such that said first gasdelivery limb and said second gas limb are bilateral and configured tobe disposed in a parallel configuration with respect to the temporalregions of the patient, said second gas limb configured to evacuate gasfrom the mask; wherein the first gas delivery limb is configured todeliver and direct a cross-flow of gas, across the nose and mouth of thepatient, from the first side region of said frame portion to the secondgas limb when the front portion is removed from the frame portion.